Interior LED Changeover (uhm...Looooong)
 

If you haven’t yet switched to LED instrument lighting, you just don’t know what you are missing. This of course is my opinion. However, look at the new cars out there, they use LED. Why?...because they last longer, draw less current and produce a vivid light with distinct color. In comparison to incandescent filament, it is like comparing the point at which the world changed from candle light to incandescent. It is just the technological succession in lighting.

I changed out every bulb in the interior with the exception of several of the cluster bulbs which I will address in a bit. It is recommended that if you are rear lighting a colored lens, that you use the same color bulb. I disagree…at least for interior lighting. Exterior, I would follow this suggestion. There are a few instances where I used LED’s when it wasn’t necessary. I already owned them and tested, so I may have just left them in. Another thing to note is that I did this on a 1993 GTS, your instrument cluster, clock light and cig lighter light may be different.

I wrote this up to help those who have considered this, but didn’t want to assemble or couldn’t find all of the info in one place. I hope this helps.

Also, let me say now that I used Wojtek, of southern California’s website as a guide for my change over. He is a fantastic fellow for doing the research he did to make these changes possible. Of course, I had embellished on a few things as maybe you will as well. Please use his site as a guide to help you through your modifications.
http://members.cox.net/my_1987s4_928...m#illumination)

NOTES:
1) LED’s for the most part are polar specific, meaning there is a positive side and a negative side. They MUST be installed correctly in regard to the polarity of the circuit
2) Have a 9v battery with two leads and alligator clips at each end. This will allow you to not only check polarities, but also check your work as you assemble and install. You don’t want to get it all back together and find out you have a bulb 180 degrees out of polarity or a bad connection or improper lighting adjustment as in a few cases.
3) Buy extra bulbs! You will undoubtedly get a bad one or two, break one or two or lose one or two.
4) These bulbs all work off of a 12v system, DO NOT apply more than 12v to any of this stuff, ESPECIALLY the instrument cluster.
5) At the bottom is a reference chart as to what type bulb goes where
6) It is difficult to take accurate photos of this type of lighting as it seems a high end camera is the only option. That I don’t have so my best efforts were made to get the best possible photos that I could.
7) DISCONNECT THE BATTERY BEFORE YOU DO ANY WORK ON ELECTRICAL.

COURTESY LIGHTING
The first and easiest is the courtesy lighting throughout. 6 lights total. Festoon bulbs, 4 are the same for the doors, rear overhead/dome and rear hatch. The glove box light is a shorter festoon type bulb. The center light above the mirror is basically a reading/map
light which requires a brighter bulb. This will take a more intense bulb for actually reading something at night. BTW, this same bulb will work well for the engine bay light if yours is of the festoon type. (These have such a low draw that you can leave the hood open all day and the bulb will not get hot nor run down your battery. As for lighting at night, they do as good, if not a better job under the hood)

DOOR MARKERS
These are of the bayonet type and I used Red. I think white would work well, but after all is said and done the difference in the filament and the LED is hardly noticeable. This is due to the thick red lens of the door marker.

CIGARETTE LIGHTER
I removed mine and ditched the bulb, but it uses the same bulb as the pod switches.

CLOCK
Rather easy to get to. A fixed base bulb with a 1/4 twist located at the rear of the unit.

ACKNOWLEDGMENT BAR
Geez, I have seen all types of these things. All I can say is there are 2 lights in mine, one for the AC button and the other for the door lock button. You will need to remove this unit and disassemble…just do it with care. It is possible however, to just replace the AC bulb by removing the button itself at the face of the unit. By squeezing the opposing ends, you work the cover off. This will give you visible access to the bulb. If you have never done this, then I recommend playing it safe and disassembling the thing…it’s quite easy. As for the door lock button bulb, it is a soldered in place bulb. I chose to leave it as is since it is a two stage light that would need a resister soldered in. The quality of lighting is pretty vivid to begin with and I expect replacing with an LED wouldn’t be worth the work. You guys with the blue and green buttons, well, make your best choice.

HVAC
This is the fun one! It’s going to require a strong stomach, steady hands and craftiness. ;) Let me explain how this thing works before I tell you how to make it better. There are two wedge based bulbs in here that for the most part, are directed and reflected towards the temperature/function plastic lens in the center of the unit. Then what you have is fiber optic lighting that is piggybacked off of these two bulbs. If I recall correctly, there are two fiber optic lines from each bulb, two on top and two on the bottom. For both top and bottom, one line runs to a slider knob, lighting the knob face and the other to the rotary fan knob, lighting the numbers and fan HI and LO.

To improve this, you are going to have to improvise a better set up. First, you are going to have to remove the existing bulbs and then you are going to have to rewire from the circuit board for the new LED bulbs as they require a 1w_200ohm resistor. This is because what I used was a bare wire lead LED not in any kind of base. Most base mounted LED’s have a resistor inside. Brush up on your soldering skills cause you’re gonna need it. You could just use replacement wedge base bulbs, but the beam pattern is not going to allow you to get a good enough light intensity through the fiber optics. After you have fit your resistor and wired your LED, you will need to fit the bulbs into the openings where the original bulbs were. The issue you will now be faced with is that the LED’s do not have a full omni-directional lighting pattern that a filament bulb does. The LED’s are projective or for the most part, uni-directional. I tell you this because the bases of the fiber optics are set perpendicular to the bulbs. When the LED is pushed all of the way into its socket, the fiber optic base meets the LED behind the projected beam. In essence, you are going to have to get the bulbs back a little so as to allow the fiber optics to catch enough light to brightly do their job. Having the wire leads to the LED’s allows you to make minor adjustments for this.

As for the fiber optics, slip them back into the same sockets to adjust the LED bulbs. I had also drilled a little deeper into the slider lenses to get a brighter light at the slider head. From the fiber optic lines...just be careful if you do this so you don’t to drill all the way through. You will end up needing to fill it in and start over again. I am sure some kind of glue will work well enough to fill the hole, but best to avoid this of course.

Lastly, I lit the fan knob itself. No, it has no lighting. I took the top pair of fiber optic lines and added a third line. I made the fiber optic line with several strands of fiber and heat shrink. I opened up the coupling where the fiber optic meets the LED bulb and stuffed a third line in there and then re-crimped. It’s a bit tricky, but you have to run the new fiber optic line to the back of the fan knob bezel.

All in all, you are going to have to pull the knobs and sliders off and really disassemble this thing to get to what you need to make it work. Refer to Wojtek’s site to help you with visuals and illustrations. You will need to be pretty good with a drill as well. ;)

INSTRUMENT CLUSTER
I did a bit of testing with this part. I ordered several LED’s to see what colors would work best. I had replaced the 4 main back lights with the proper LED replacement bulbs. I have to say that if there is a single best thing in using the LED’s it is this right here. It totally changed the viewing of the instruments and daylight viewing is very vivid….no more squinting to see the gauges. Replacing these bulbs and all others in the cluster is very easy. Getting the cluster out though, takes patience. I was removing the whole shebang before I read Shocki’s post on removing the cluster in 15 minutes. Not sure I agree with the time frame, but the idea works and works well! So once you have the cluster out, you will need to release the 4 locking clips and carefully open the back housing. There is a multi pin plug that connects through the backing so go easy.

The main back lighting bulbs are wedge and plug into the bases. If I remember correctly, you can check for good bulb seating with the 9v as there are exposed leads on the outside of the base holder. Make sure you correctly place the bulbs with their respective polarities into the circuit board You can check this with the the rear of the cluster closed and tabs locked using the photo shown below. Do this as a final check JUST for the back lighting. You will undoubtedly be sure that all 4 bulbs are properly seated and polarity correct.

As for the rest of the cluster, it is entirely up to you if you would prefer LED’s. They are all fixed base bulbs. I think it is important to note here, that LCD and LED do not mix well! I had tried different combinations and due to the LED’s being a focused or projected beam pattern, LCD requires a wide “washed” pattern of light.. I used white, yellow and red LED bulbs for testing and they just did not do as good of a job as the original filament bulbs. However, I did change out the lower LCD display to 2w VW bulbs (green base). These are the bulbs with red latex covers over them, so you will need to transfer the covers. The red now jumps out of the display. Use the original 1.5w (yellow base) bulbs for the normal display as anything brighter just adds to the background lighting and the contrast/definition is not as good. Besides, this panel is as crisp as it is going to get using the filament bulbs.

I did decide to change a few bulbs over that got a fair amount of usage and I did like the way they looked with the LED bulbs. I used green LED’s for the Parking Lights and Turn Signal indicator. I had tried a blue LED for the Hi Beams, but white worked much better. You guys that have automatic tranny’s may want to use LED’s as I have a feeling they would work much better than the filament bulbs. There are a couple more that I probably would have changed over like the Low Fuel and the PSD, but I don’t see those indicators much of the time. For the most part, the indicators around the cluster are pretty vivid and bright to begin with…especially the red so I saw no need to fool with them. Changing out really wouldn’t make much difference color wise. I did have to modify the backing cover to close over the Parking Light LED base. It stuck too far up so I drilled a hole to accommodate.

Make sure you check your connections and polarities before you button every thing back up. Just to be safe, when you get the cluster reconnected to the four harnesses, reattach the battery and just turn the key to the #1 position to make sure everything functions. You can check your turn signals and such at that time as well. If it all works, disconnect the battery and finish putting everything back together.

POD KNOBS
If you’re doing this mod, may as well do the instrument cluster as you will now have to remove the pod completely. All knobs/switches need to be disconnected and removed. You will need full access to the switch wiring. Following Wojtek’s schematics, you will need to install resistors to the switches that will dim when not in use such as the Fog, Rear Defrost and Hazard. Solder in the resistors and heat shrink over them. As for the wedge base bulbs, they will not slip right into the switch socket. I had to file down and custom fit the bases some to allow the bulb base to fit properly. This is where the 9v battery came in handy too. There may be other wedge base bulbs out there by other manufacturers that will fit better, but which ones, I don’t know. Again, polarity has to be correct.

This mod to the lighting was way beyond well worth it. It’s one of those things that you wonder how you ever lived without it. I know there is concern about dimming as the dimmer switch hardly works now. I personally don’t think you need the dimmer switch for LED as the light is not necessarily brighter, but more vivid and concentrated. There are dimmer switches available for LED lighting, but that is something you will have to decide if you need. To me, the light isn’t all that bright or distracting at night. Daylight viewing is excellent and to be honest, I never knew I had it until I installed the LED’s. Your headlight switch and cluster are illuminated all of the time as soon as you turn the key past the #1 position. No more do I have to squint to see the gauges during the day. Clear as a bell and easy to read anytime. As for the rest of the lighting at night, no longer is there an weak amber glow to anything, it is all crisp cool white and very vivid, not to mention the updated look that you get. It’s a fun and satisfying modification that is well worth the effort. Also, there is no issue with current draw and faulty lighting issues. The two stage lighting on the pod switches works great also!

I have made a list of the bulbs and their respective placement in the car. I hope this will help others if they choose to do the change over. I had gotten all of my bulbs from SUPERBRIGHT LED. http://superbrightleds.com I think other LED companies may have their own part numbers, but it shouldn’t be tough figure out what you need.

The following is for the last inception of the clusters with the LCD info screen. I have listed the possible bulbs for replacement if anyone is interested.

INSTUMENT CLUSTER
WLED 5-LED WIDE ANGLE WEDGE BASE LED BULB [White]
(4) Instrument Cluster Main Back Lighting

#74 WEDGE BASE LED BULB (see colors next to item)
(4) LCD Display [White]
(4) LCD Display [Red]
(6) P R N D 3 2 [white] or P=(1)[Red], R=(1)[Blue], N=(1)[White], D 3 2=(3)[Green]
(1) Low Fuel [Orange]
(1) Low Oil [Red}
(1) Low Battery [Red]
(1) High Temperature [Red]
(1) Brake [Red]
(1) Parking Brake [Red}
(1) Seat Belt [Red]
(1) Antilock [Orange]
(1) Trailer Connection [Green]
(1) Turn Signal [Green]
(1) Hi Beam [White]
(1) Tire Pressure [Red]
(1) Parking lights [Green]
(1) Check Engine [Red]
(1) Stop Lamp [Red]
(1) PSD [Green]

POD SWITCHES
#74 WEDGE BASE LED [White]
(1) Headlight
(1) Fog + 1K ohm 1w resistor
(1) Trip Reset
(1) Rear Window Defog + 1K ohm 1w resistor
(1) Hazard + 1K ohm 1w resistor

CIGARETTE LIGHTER
#74 WEDGE BASE LED [White]
(1) Cigarette Lighter

INTERIOR COURTESY LIGHTING
HID HIGH POWER LED FESTOON BULB 42mm [White]
(1) Map Light
(1) Dome Light
(2) Convenience Light
(1) Cargo Light

GLOVE BOX
3022 x 4 LED FESTOON BULB 30mm [White]
(1) Glove Box

HVAC
SUPERBRIGHT WHITE LED 11C 5mm [White]
1w_200ohm resistor 1W120-NTE HVAC
(2) HVAC (two sliders and fan switch)
#74 WEDGEBASE LED [White]
(1) HVAC (back light)

CLOCK
74 WEDGEBASE LED [White]
(1) Backlight

AC
#74 WEDGEBASE LED [White]
(1) Button Backlight

ASHTRAY
BA9s 1-LED Bayonet Base bulb [White]
(1) Cigarette Lighter (backlight)


DOOR
BA9s-x-WV WIDE ANGLE BULB [Red]
(2) Open Door Marker


If you have any questions, I will do my best to answer them. Again, I apologize as these are the best photo's I can come up with at this time. It is truly something you have to see in person.

http://forums.rennlist.com/upload/led_1a.jpghttp://forums.rennlist.com/upload/led_4a.jpg
http://forums.rennlist.com/upload/led_5a.jpghttp://forums.rennlist.com/upload/led_6a.jpg
http://forums.rennlist.com/upload/led_33ab.jpghttp://forums.rennlist.com/upload/cluster_reara.jpg
http://forums.rennlist.com/upload/led_3a.jpghttp://forums.rennlist.com/upload/100707_9a.jpg

Though ridiculously blurry, this is about as true as it gets in regard to the actual colors of the dash and console.
http://forums.rennlist.com/upload/cl...n11a_copy1.jpg

Keith
DAMMM......I'm very impressed.....that looks bad ass...just like my new acura......

Looks great, but surely the dash lights won't dim anymore with the rheostat?

upon further inspection of your car and mods, I have decided I hate you.
:D


Great way to top off the stereo install. Very professional results. Love it. I went with glo gauges and LED's everywhere else. Really updates the look on your shark.

Excellent, Keith! I have done some of this too, but not the cluster or console lighting yet, so this really helps.

I used the red LEDs as you did for the door edge lights. The red LEDS are much cheaper than white. I tried both and even with the deep red lens, the red LEDS actually looked better.

Don't forget the license plate lights, even though that's exterior. The pure white LED light looks very sharp in place of the yellow incandescents. 36mm festoon.

If you look real hard, you can see them dim from bright to bright ;) Actually there IS a tad of a difference, but as I had mentioned in the long winded first post, there is a separate unit you can get to dim the lighting, but I really see no need for it.

Bill- The exterior lighting is on the list of future things, right down to Xenon bulbs. There is an exterior mod I must do before anything else though. It's radical...and my next "must do" project.:evilgrin:

OK, I gotta do this. At least on the instrument cluster. At night I really have to look hard to see the gauges. Very dim.

Kewl!

Can't wait till my stash of #74 bulbs arrive.
Dive into pod to reactivate odometer and plop in 4 white led's. Hope I don't end up with 'Tokyo by Night' instruments.

Maybe the LED will revive my long dead headlight switch. And putting an LED into the AC button should make that button less hot after a nice long drive. Hope it's the filament bulb heating up the AC switch and not weak contacts.

Thanks for pointing the way, Keith.
(Praying for 'Assembly is reverse of disassembly')

WoW!!! Great write up! Thanks for doing the homework and especially for sharing. Looks great by the way!

I actually ordered a bunch of bulbs for future cluster work and all courtesy lighting a few days ago. Some T10 wedges for the main dials, and a variety of T5's for the instrument lights and pod switches.

On the pod-bulbs; I did notice that some ebay vendors sell shorter wedge-base led bulbs in the T5 size (most are 20mm.. I've seen a few vendors with 14mm).

Might be enough to not have to file them down to fit?

The issue is not the length, it is the diameter of the base. With the filament, all you have is the wedge glass and the total diameter of the glass bulb slips snugly into the switch socket. The LED's require a base and micro resistor fitted at the bottom of the bulb in the base. I am not sure there is any getting around this unless someone is making them specifically for this type of application. I have small hand files for craft/precision use.What I ended up doing was grabbing a hold of the bulb with some small pliers and running the base back and forth over the file which was held flat on a surface. Yea, I know, a bogus way to do it, but it got the job done. The other option I didn't try was a Dremel with the sanding barrel/wheel attachment. I can't remember why I didn't at this time....might have been too lazy to bust out the power tools ;)

In your post, you had referred to "#74 wedge base LED." On your link which ones are they? Even though the resolution isn't great, it does convey the vast improvement of LED over conventional bulbs.

One other thing I was wondering is do the later 928s have backlit instruments?

You will have to navigate your way from the Home page > LED Bulbs & Products > 12 Volt Car Bulbs (READ the info on the page and then move on to the next page) > Continue To Car Bulbs > Miniature And Wedge Base Bulbs, then scroll down to Instrument Cluster and Gauge Backlights. Click on MORE INFO for...more info.

I have tried so many different camera settings, lighting, angles and distances, and I just can't get my camera to capture what can be seen in person.

I think from 1990 on, the gauges are back lit. Wojtek addresses the face lit gauges, but that just looks too bright for my tastes...I just want to see the needle and dial.

Very nice. I need to get started with mine. It really makes the console design look ten years more recent.

One thing I didn't mention, was there is a possibility you will get all of your work complete only to find a week or month later, you have a faulty bulb or two. I have had issues with the 4 cluster back light bulbs flickering and blinking after they warm up..and NOT in sequence! This was one of the reasons I waited so long to post this thread. I called Superbright and they had discovered that the maker of the bulb had some faulty resistors inside. My instrument panel looked like a discotheque for a month or two until they had a new run of these bulbs. I certainly explained to them the PITA factor for replacing these bulbs. Now, I have one that looks a bit "nervous" as it is flickering a tad...pisses me off. However, I have noticed a huge difference in the green colored display. Driving in the wet causes the PSD to light up at times and the difference in color from the parking and turn signal displays is night and day. So I am going to replace the PSD bulb to LED. The orange and red displays do not need replacing just to reiterate.

To my knowledge, LED's are quite reliable and I just got them at a time that there was a bad batch sent out. Superbright replaces and ships at no charge of course. I discovered a way to check the bulbs beyond the 12v battery check...add another 12v battery to get you 18v's! ONLY do this with the bulb itself and NOT installed in any components!!! Just take a third alligator clip lead and connect the two batteries from the "+" of one to the "-" of the other. Then use the "+" from one battery to the bulb and the "-" from the other battery to the bulb...18v's! This will get the LED working harder and shining brighter, allowing you to see if it is going to crap out on you. If it doesn't start to blink within a minute, it is fine. Actually, I highly recommend checking all of your bulbs before you install them, something I should have mentioned in my original post. Throwing 18v's to these bulbs won't hurt them for this short period of time to test.

so 12 + 12 = 18?

Two 9-volts perhaps, but two 12-volt batteries in series will give you 24V...

...at least, it did when I went to school! ;) (which is what my dad always used to say when I made one of my -frequent- mistakes!)

Did you mean to type 2x 9V batteries, or did you mean to type 24V? -The way it stands now, the math doesn't make sense.

Keith

Leds are prone to fail when facing over current conditions.
(Which will occure if you apply higher voltage than the series resistor used was ment to face)
To limit the current it is common practice to use a resistor in series with the LED.(most normal LEDs are designed to run at maximum 20mA, superbright can be 30mA up to A level)
To define the correct resistance value you should use Ohms law.
(E=RxI or in this case R=E/I where E=Voltage, I=current and R=Resistance)

I assume this has alreday been done to these LED lamp bulbs as well to make them usable in 12-14VDC applications like in cars.
So be careful applying higher voltages since this might end the life or significantly shorten it.
The reostat for the instrument lighting is no good for the LEDs.
There are many benefits with LED's compared to traditional lamps.
Most of the energy applied to an LED will transmit into light instead of heat which is the case with traditional lamps.
The 'turn on' time is much shorter which is great for breaklights for instance.

For more details on the technology and current limiting calculations check out these links:

http://ledcalc.com/

http://www.the12volt.com/ohm/ohmslaw.asp

http://www.theledlight.com/ledcircuits.html

http://ecmweb.com/mag/electric_under...ed_technology/

/Peter

Keith-

I was looking these up and couldn't find these. Can you provide an updated description based ont he SuperbrightLEDs website? I figure I might as well do this over the winter too! Thanks.

Edit: Obviously, I'm looking for the bulb reference. I figure I can pick up the resistor from Radio Shack or some place similar.

Bump

I think i will try and replace the door lamps with some of these 42mm LED lamps. I find them all over the internet but does a place like Frys Electronics stock these things? If so i will just go there, anyone?

I stock them... in warm white and cool white. I also have some red and blue ones in stock.

BTW: I don't recommend doing the dome or trunk lights in color - you won't find anything in your car. Colored LEDs in the doors are OK, but on the 90 and later models you need the white type again above the fuse box (if you care to see the different colors of fuses in case of a problem)...

color as in what, Red like a ricer? I would hope people only use white. The reason i want to change them is that the amber illumination is ok, but i think white would look nice.

I was just in an autozone and they have fiberoptic stuff to run all around the interior of your car in many different colors. On most cars this looks like hell. But I remember when the current S-Class came out you could get it (i'm sure you still can) with an interior illumination ambient package that had a fiberoptic line in amber running from the center of the dash under the wood trim, into the door panels front and rear. I really liked the way this looked on that car. It was very tasteful, i was thinking that with the 928's door panel design that you could run a strip under the armrest and inbetween the carpeting for a nice effect. But i dont know how it would carry into the dash.

The lighting strands that i am talking about, like in the BENZ above are like $20. I may buy a set and see how it looks. Thinking about it i think the passenger side would be easiest with a dual airbag car. Run the strip from the lower portion of the door panel, then into the lower dash at the point where the glovebox lid opens. and that could carry into the center console. You could light it up where the black plastic dash meets the carpet.

But you may have some issues with how the lights looks against the carpeting, that may distort the light somewhat and look like crap. I think i will try it actually. Could be a nice bit of mood lighting when its on, and look totally hidden when its not on.

When i saw the pic of the S-class with that lighting i thought it was a great idea.

BTW, Keith the instruments look AWESOME. I like the different colored lighting that you as well for different switched.

Nicole, I would prefer to just buy these things locally. Again, anyone know if Fry's sells this stuff? The Frys in Austin is a hassle to get to otherwise i would just head over there.

Damm You; I have been avoiding tearing into my my dash to fix a few things now this lamp write-up. When will it all stop, I may have to list this site as spam, seems I do everyting I see on this list makes me go out and do it:icon501:

Ryan...just remember this.."Less is More". Forget about the strand lighting. It will end up looking like an RV. JMHO

I am about to do the dash of the 85 I have and it is an older car. When I am done, I will do a write up on that.

Holy Hell Keith! Your instrument cluster blinds me just looking at the pictures! LED is definitely something I want to do with my shark also. That looks fantastic!

I agree less is more. I never would have considered the fiber lighting until i saw it in the S-class.

Its pretty cheap, I would need 2 light boxes and 16 ft of fiber to do what i want. The fiber would cost $8, the boxes, i dont know maybe $20 each. I may try it out and if i dont like it sell it to someone with a civic.

OH FYI, Fry's doesnt have anything like what i am looking for. I will try online.

Some of the autopart stores like PepBoys are starting to stock LED bling items, but they don't have all the various replacement bulbs like Nicole.

nicole can you PM me prices, or are they on your website?

I have read Wojtek's page on HVAC illumination, but am unsure about how he has lit the "Knob". I think I understand the need to make a slot in the Plexiglass for the Fibreoptics, but how does it then enter the back of the Knob. Does the Knob have to come off (If so how) to drill a hole in its back?

Also has anyone successfully backlit or otherwise illuminated the Window/SunRoof/Rear Wiper Switches? The idela would be modifying the switches to be translucent similar to the Pod Switches, but this seems far too difficult, and maybe a bit of trial & error = $$$. Perhaps a piece of Plexiglass semi hidden in a U shape around the front of the switches and light with a couple of LEDs from beneath? There appears to be enough clearance....

Jim Reay
1991 S4 (ex Japan)
http://www.youtube.com/watch?v=Qds1qoH5LW4

Keith - I wouldn't recommend the dual battery stress test idea... I think testing them like this - while it may weed out some prone to failure it may just create latent damage in others leading to later failure that may otherwise not have happened. If you are to stress test with elevated voltage it should not be so extreme 18V may be a more acceptable level its more like what a manufacturer might do for "burn-in" testing (24-26V probably not).

LED's in general are very reliable and have a long life expectancy.

However super-bright LED's are a little different. There were some technology advances that allowed higher output. However you can also get higher output from just running LED's at a higher current. Doing this is just a trade off of more light output for less lifetime. In practice the cheap ones from China you buy on ebay may be a combination of the 2 things...

How do you know what you have really got .... you don't...

There are 2 options - pay more to buy from a reputable vendor - who probably used better sources and at least may offer replacements (though for many applications replacement is huge PITA). Or you can add an additional series resistance (there is one built in to bulb replacement LEDs which sets the current level at a given voltage). If you add aditional resistance outside the bulb you can limit the current & brightness a little to move yourself along that tradeoff towards more reliability. Porsche does this even with the incandescent bulbs in the hard to reach locations - on incandescents less voltage dramatially increases lifetimes.

The existing Rheostat is such a series resistance - but it goes to all the bulbs and it is sized for the current load of incandescent bulbs which is way too little resistance.

You may find you need different resistances to each bulb type to get appropriate adjustments so fitting a new higher value rheostat may not be the answer.

Alan

Alan, I don't recall what you are referring too and I haven't gone back over everything. I am sure what ever I said, I meant was that 18v should be applied just to the bulb in short term wth 2 9v batteries. I have had no adverse affects from this, but if you had "quoted" me, I might be able to address this better. Sorry for any mis information.

Jim...you will remove the fan knob and drill a hole at an angle in the back side so that the fiber optic line points right at the fan picture on the knob. Just drill in a location of the knob so that it will not impact its rotary function. Drill as close up tto the top of the knob as possible...sorry, I don't have a pic of what I did.

The switches have been discussed in different threads in the past, but I personally see no need for it. There are some glow in the dark stickers that someone had made but basically, drilling out the switch faces and installing something else, then uplighting seems to me to not be worth the time. I have heard several say that they hate where the switches are. I love them as I never have to look at them and can just lay my hand over them and know exactly which switch I am on without taking my eyes off the road. To each his own. If you come up with something, post it, I am sure there are others that would follow your lead.

OK I'll quote you - maybe its not what you meant... but its what you said... and others may follow this advice...

Admittedly (and as noted by someone after) the math is a bit flawwed - but some people don't pay attention and may follow the idea...

2 x 9v batteries in series is OK due to both the lower voltage and those batteries much much higher internal resistance.

Alan

Yea...my bad and I missed the correction. Yes, 2- 9v batteries. I had 12v auto source on the mind I guess.

Just noticed one of my #74 LED (dash pod side lights) had 18V stamped on it.
Tested one white wide beam LED in the headlight switch and boy is that thing bright.

Going to switch out the rest of the pod switch lights now that I've found out about the 2 screwdriver/needle nose trick to free the switches from the pod.
(Can't get the small slippery old bulbs out of the switch with them buried in the pod)

Haven't tried it, but I think crazy glue on the end of a plastic toothpick might work.

Ernie - Slip some clear plastic tube over the bulb end - you may have to experiment with size - I had some to hand that worked fine - this was a tip from someone else that I tried and it worked very very well. I think it helped to stretch the end open wih some needle nosed pliers then slip it over the bulb and wait while it contracts back...

Alan

Thanks Alan and Keith.

Ain't fun trying to manhandle glass bulbs.
I'll see if I can rustle up some small rubber tubing.
Might even try some glue in the tube as lube and let the sucker bond to the dead bulb.

It's like the Zuffenhausen crew had too much model railroad experience and decided to doll up the switches with some of those wheat of grain bulbs.

Glad those #74 LED bulbs are manly and easy to manipulate. The wide beam bulbs also are flat topped for easier handling.

Keith,
I have been working on a somewhat similar upgrade. I have a couple of questions about the the pod switch led installation.
1) How did you file down the bases for the bulbs to fit? A small rat tail file or something?
2) Following Wojtek's schematics, do simply cut the particular wire and solder in a resistor in the line? Would any old radio shack resistor do the trick?
Still lovin' your car,

Sorry, been out of touch for a bit.

Any Radio Shack or electronics store for the resistors and just solder them inline. Cover with heat shrink tube.

For the filing, you can use a rat tail file, but that takes a while, I got smart and used a Dremel with a little barrel sander. You basically have to make a better wedge shape at the bottom of the LED. Don't try to modify the socket, I tried and F'd one up and had to replace it. There is enough plastic at the base to remove material before you get into the bulb. Trial and error.Take your time and you'll see it will work.

Good luck.


BTW, I never really posted any pics, but I did this same conversion to an 85. Dash and all. The instrument gauges were front lit of course, but the conversion worked out great. BTW, I just wired past the dimmer wheel....that thing is useless and there is no need to dim these.

Keith, Thanks a million. I am really glad I asked, I would have totally tried to file the socket and not the bulb. I too have just deleted the dimmer, I am using LED's to front light the needles and a speedhut reverse glo el gauge faces on my 82. Looks pretty nice (not nearly as nice as your car), the LED pod switches will be the finishing touch.

Here's a pic of the 85, though it was still light out. You don't get the full effect, but you can see how vivid the lighting is even when it is dusk. Note the fan switch is lit aas well ;) Good luck Bob!
http://img360.imageshack.us/img360/4896/8515mw4.jpg

So - what's the process involved in switching a frontlit cluster to a backlit cluster? Are they a plug-n-play swap (obviously losing the trip computer/odometer, I guess)? If not, how hard would it be and what would be the steps?

No Need.
Once you upgrade, the LED's on the frontlit setup look great!

That pic sucked,
Hopefully this is a little better

another must upgrade. amazing my 968 was just 2-4 years away from so much rad stuff.

Am I correct in remembering that you can no longer dim the LED's?? That to me seems to be a disadvantage. Are the LED's bright enough to bother your night vision?? I typically like to keep my pod lights pretty dim, but that could just be me.

If anything, it would be nice to at least be able to turn the LED dash lights on and off... Maybe with an additional high intensity wash switch in place of the dial? How much are the dimmer units that were talked about?

I have been gearing up to do an LED conversion. I didn't realize that there are wedge shaped LEDs available - silly me. What I am trying to accomplish is replace most of the dash/console incandescents with tri-color LEDs so at the push of a button I can change the color of the light. Simple setup would yield 7 different colors - red, green, blue, cyan, magenta, yellow, and white. I popped off one of the pod switches and placed the lens over one of these LEDs - looks really nice. I am afraid of not having enough space in which to wire the LEDs though, as there are 4 leads per LED. Also, I'm not sure how to handle the power supply; I bought some 5v fixed output voltage regulators @ radioshack which accept up to ~30v, so between 12.6v at battery and 14.4v with engine running, the LEDs should remain the same brightness. I want to use the existing wiring and install a voltage regulator just after the fuse/wherever the lights get common power source from (headlight switch?). Only issue is that I would have to swap all the lights at once because I couldn't have LEDs and incandescents both work on a 5v circuit.
Is this too complicated? Should I go for single color LEDs instead?

in my swap i just did the instrument cluster backlights...all others (radio/hvac/pod switches) are still in the traditional ambers.....my dim still works, but not smoothly, for instance, when i scroll the dim, the lights fliicker until it is at just the right setting....but it works. i have them set as low as possible, because at night they are very bright...when the headlights are off tho, and cluster is in daytime running mode, its perfect and they are much clearer for daytime driving...they look like a modern audi cluster now http://images.paultan.org/uploads/20..._dashmeter.jpg
i also changed the obd lcd to all red, it looks much more modern

Still waiting on that '85 write-up.

You missed it. I don't remember exactly where I posted as it was in the midst of several post, but the car was in this thread https://rennlist.com/forums/928-foru...ts-coming.html
The pics are now gone as the hosting site pulled the plug, but here are pics of the car and dash. There is not much difference in the changeover for any year car except for the lighting of the instrument cluster....that info can be found all over Rennlist.

http://forums.rennlist.com/upload/85_11a_copy1.jpg
http://forums.rennlist.com/upload/85_14a.jpg
http://forums.rennlist.com/upload/85_15a.jpg

Wow! Everything about your car is so amazing.

Is that smoke screen on the right button and left button for the rockets?

I really love the lighted HVAC fan knob.
I replaced all backlights on the knobs in my 86.5 (with traditional bulb), and was really disappointed to see porsche didn't bother the fan knob, despite is has the same look as the pod controls.

In case I upgrade to LED, I am certainly also doing the fan knob!

http://forums.rennlist.com/upload/85_15a.jpg

I love the overall look of the black car, but that steering wheel really skrews up the total look.
Off coure that is just my opinion, but I felt I should share it :-)

BTW, I have that steering wheel and used to have it in my 944. I painted the "Vulcan" grips black. I think it looks much better without the contrast. Car still looks awesome.

I want those wheels!

Keith, are these the LED's you used? If so which ones specifically?

i.e. which of the below did you use for each applicaiton?

http://www.superbrightleds.com/cgi-b...cs%2F74-x.html

74-x

74-xHP

74-xHP3

24-xHP

finally!, I know you didn't ask me, but I've got an early draft of what will ultimately be a rather comprehensive guide to upgrading interior lighting to use LEDs. The section entitled "Parts Summary" near the end with recommended bulbs is complete, so feel free to make use of it.

Converting Porsche 928 Interior Lighting to LEDs

Major thanks to Keith—and a couple of other people I mention in the document—for the trailblazing work they did in this area.

Ed, thanks for that. We've had some not so good luck with some of the kits that are available.

Link doesn't work for me?

That's because you're Irish, matey! Works for me. Thanks Ed, very thorough.

Looking good! Now who is going to put together a kit, or better yet, do the actual instr. cluster modification if I send them my board? Love the LED lighting idea, but nowhere near that 'electronic' to tackle this mod ...

I’m a little confused on how to light the fan knob on the HVAC unit, and before I start drilling, I thought I’d ask the experts. I understand the need for the additional fiber optic cable from the bulb to the back of the knob; I’m just not sure how that cable is run. Does anyone have a picture or two of how they did it?

Below in “Wojtek’s” diagram, it looks like he cut a wedge around 25% of the base’s radius, as close to the “Hi/Low” piece of Plexiglas for the fiber optic to run through. I assume this is to provide slack for the cable as the knob rotates 25 degrees when switched from hi to low. The fiber optic cable then sticks through the wedge he cut and then goes into a hole drilled into the backside of the knob.

However, in Keith Widom’s write-up, he said “...you will remove the fan knob and drill a hole at an angle in the back side so that the fiber optic line points right at the fan picture on the knob. Just drill in a location of the knob so that it will not impact its rotary function. Drill as close up to the top of the knob as possible.”

Keith lost me on the “drill as close to the top of the knob” part because Wojtek’s diagram would have the cable entering at the bottom. I’m also wondering why cut the 25% wedge in the base as the knob is what rotates. Since the knob is the piece that moves, would cutting a 25% wedge on the back of the knob and just have a single hole in the base unit for the fiber to feed through also work? Or would that cause a ghost around the back of the knob??

A picture would help a lot! Thanks / Bruce

I can get a bunch of photos this evening when I get home from work; unfortunately, I just noticed that I never copied my photos of the climate control LED upgrades out where I can share them. The only one I have out there right now is below. I did use a blob of hot glue to form a lens that diffuses the light from the end of the fiber-optic filament.

I guess I need to finish up my interior LED upgrade write-up, too; the section on this is currently missing. :)

BTW, in retrospect, I wish I would have just wired up an SMT LED instead of a fiber-optic filament for this. The fiber-optic filament turned out (IMHO) to be a little too klugy for my tastes.

https://lh4.googleusercontent.com/-L...1-05-0672a.JPG

I tried using that write up but it was much too problematic.

Instead what I did was sourced a Surface Mount LED, I then glued it to the area behind the plastic piece with the fan silkscreened on it. Drilled a small hole for the wires to it, make sure they are flexible, and wired up.. WORKS GREAT! Surface mount LEDS are very flat and thin with the wires coming out the side as compared to bottom.

Here is a pic; I have since painted the sides of the fan knob so the light doesnt shine outside the edges like in the pic

https://lh6.googleusercontent.com/-N...1-05-0686a.JPG

Thank you, Ed. A couple pics would be great! Your guide has been outstanding---it's got me this far and I'm in the home stretch!

finally! - That looks outstanding. I'm kind of committed to the fiber optic solution as I've already bought a donor fiber optic tree from the "Everything's a Euro" store :p

I planned on adding/subtracting fiber strands to get the right brightness and just put heat-shrink around the strands. But in the end, if I can't get it right, I'll take your advice and just put an LED in there.

Thanks again / Bruce

OK, here are a bunch of photos. I don't have time to add any explanation right now (I'm just in the middle of painting my home office and a couple of adjacent small rooms). Just ask if you have any questions. They're in chronological order, so the first two are before I made any changes.

Click any photo for the big version.

https://lh4.googleusercontent.com/-v...11-05-0558.jpg https://lh5.googleusercontent.com/-5...11-05-0561.jpg https://lh4.googleusercontent.com/-4...1-05-0567a.JPG https://lh3.googleusercontent.com/-N...1-05-0579a.JPG https://lh3.googleusercontent.com/-3...1-05-0616b.jpg https://lh3.googleusercontent.com/-l...11-05-0620.jpg https://lh5.googleusercontent.com/-1...1-05-0622a.JPG https://lh5.googleusercontent.com/-R...11-05-0644.jpg https://lh4.googleusercontent.com/-R...11-05-0645.jpg https://lh4.googleusercontent.com/-X...11-05-0671.jpg https://lh4.googleusercontent.com/-L...1-05-0672a.JPG https://lh3.googleusercontent.com/-t...11-05-0674.jpg https://lh5.googleusercontent.com/-0...11-05-0675.jpg https://lh3.googleusercontent.com/-4...11-05-0676.jpg https://lh5.googleusercontent.com/-B...11-05-0677.jpg https://lh6.googleusercontent.com/-_...11-05-0678.jpg https://lh6.googleusercontent.com/-j...11-05-0679.jpg https://lh3.googleusercontent.com/-5...11-05-0680.jpg https://lh3.googleusercontent.com/-l...11-05-0681.jpg https://lh4.googleusercontent.com/-K...11-05-0682.jpg https://lh5.googleusercontent.com/-N...11-05-0683.jpg https://lh6.googleusercontent.com/-3...11-05-0684.jpg https://lh4.googleusercontent.com/-I...11-05-0685.jpg https://lh6.googleusercontent.com/-N...1-05-0686a.JPG

Thank you, Ed - this is fantastic! I didn't realize you had installed a dedicated LED and fiber optic; I thought you just routed another strand of fiber from the existing light. Wow!

These are great pics for anyone wanting a lesson in HVAC head 101 too.

Thank you again, couldn't have done this without you. / Bruce

Glad to see this thread is still getting some mileage. :)

One thing to take into consideration is that I did this about 4.5 years ago, so my memory is a bit foggy on it, AND, technology in LED's has taken quite a leap since then. There were only a couple of companies out there producing LED's for the auto after market. Based on what I have seen a few of you guys do, I would have certainly taken those steps if the technology existed.

The flat mount LED for the fan knob is the way to go, not only better lighting, but easier to perform. Since it was so long ago, I have no clue what I meant when I said "drill as close to the top of the knob as possible". I may have meant the center. No matter, I wouldn't even waste my time with that mod today, just do the wire and LED in the knob.

I think a couple of you guys, namely Ed, took this whole thing to a new level and I would probably follow their techniques if I had to do it again.

ADDED: Now that I look at Wojtek's diagram again, I think what I had meant when I had said "drill as close to the top of the knob as possible", I was referring to the position of the fitted knob on the pot post in the LO position...so meaning as close to 4 o'clock as possible. This would have allowed minimal movement for the fiber optic in the shown groove since the knob is turned clock-wise. Hope that makes more sense. Still, go with the new way and use a flat LED.

Thanks, Keith. Now what the hell am I going to do with this fiber optic tree?:roflmao:

That would make one hell of a dashboard ornament. Surely better than a couple of fuzzy dice hanging from the rear view mirror.

Will this application work my 82.

LOL...ya didn't have to copy the whole first page...

If you had read post #52, I had also done an 85 and stated that everything is pretty much the same except for the instrument cluster, namely the back lighting. You can search RL and find what others have done with that.

Good luck.

As far as I can tell the only difference is that the later cars have backlit gauges, as opposed to lighting from in front of the gauges like our early cars.
All this stuff should work, except for that.

Funny you should ask, because...


I was monkeying with this very issue last night. Because early gauges are front-lit (as opposed to backlit like the later 928's)I used an edge-lit white led strip (sold by Alpena at Auto Zone) mounted on the bottom of the gauge panel recess, in front of the gauges. I expected to have an issue with reflectivity off the clear plastic in front of the gauges, but it hasn't happened. I still need to finish the install with a trim piece to prevent stray light and cover the wire end, but the effect is very dramatic, and quite visible, even on bright days, and because I routed power to the strip from the incandescent lighting on the center console, I can still use the dimmer as needed. I actually left the lighting in the pod in place, because the LED strip is so much brighter, on all but the dimmest settings, they are completely washed out anyway. I'll post a pic as soon as I find my camera (again!).

As you can see, the effect is similar to footlighting a stage. At the brightest setting, the master caution light is still clearly visible. I've included a pic of the dimmest setting just before the LED goes out altogether, at which point the incandescents are (just barely) visible again.
I plan on replacing the rest of the bulbs in the panel and the console with LED, but this will at least enable me to see my gauges clearly at night in brightly lighted streets or on sunny days.

Epilog 1, star date 141397
 

I wrapped up my LED conversion today and thought I’d post a couple pictures to help anyone who does this in the future.

I took the advice and installed an LED in the fan knob of the climate controller rather than running fiber optic to it. Like Ed used to light his fiber optic, I used the same size LED (5 mm, 15° discrete LED) in the knob and simply drilled a hole in the knob as close to the center of the shaft. I also drilled a hole at the 8 o’clock position in the area behind the knob routed the wires out the back. To tone down the brightness of the LED, I inserted a 2.2K ohm resistor.

You’ll notice in Ed’s pictures he used silver paint in the cavity area where the main LED/bulb is (the area between the upper and lower sliders) to increase reflection of the light. I followed his lead but instead used 3M reflective tape and applied it to the top, bottom and rear of the cavity.

The A/C button was easy; the button pulls right out and then so does the bulb. You have a 50/50 chance of getting the polarity right the first time you insert the LED :) Also no issues replacing the cigarette lighter backlighting; BUT, my bulb on the GTS was different than Ed’s—mine was a BA7s LED, the same as the A/C button.

Unless you have hands the size of a munchkin, you probably won’t be able to remove the side panel of the center console and reach back behind the clock to install the LED—there’s just not enough room. And considering the cost of a new clock, I didn’t want to risk cracking the face of it trying to pop it out of its holder. So instead, I removed the front trim and then had easy access. I posted a couple pictures below to help anyone who’s never gone in there…

I couldn’t be happier with the results. Despite the appearance in the picture, it doesn’t have the “glow” when viewed with the naked eye. People have described it as more vivid, not brighter. I’d agree. If I ever go into the climate controller again, I think I’ll capitalize on Ed’s idea and install another LED in the unit and dedicate it to only brighten the slider knobs. No doubt, it would make them much brighter. I also think it would take very little effort to replace the plexiglass that has the fan control speeds (low, high, etc.) and mount a dedicated LED or two in there as well. But at some point, it’s probably overkill…

Thanks again Ed, Keith, Chuck and others here on Renlist. Couldn’t have done this project without you! And I’ll say it again, Ed, your guide is excellent!

Here's the pictures of the climate controller:

Epilog 2, star date 141397
 

And here's the pictures of the clock and final pictures:

Nice work, Bruce. Darn satisfying, isn't it? :cheers:

Thanks for posting those clock pics; very useful.

FWIW, I actually did manage to swap bulbs on the clock without removing the clock. It is darn tight in there (and I don't exactly have small hands), but I found that you can actually use a six-point socket (I'll have to consult my notes to see what size) to remove and reinsert the bulb assembly. Not super easy and requires patience (IIRC, I think I was using the socket without a driver, turning it with one hand on each side), but it worked for me.

Great job Bruce!

Nice job!

It really isn't difficult to go overboard with some of these things, especially now with all the LED types of lighting available. Who can really see those numbers on the rotary dial? Why not just lose that dang thing and install 3 pin head LED's and lose the plastic Hi/LO plate around the know. Make a black panel and install 3 LED's that light up in succession as you twist the fan knob. (all three lit when on HI). Or, use 3 colored LED's that will just reflect into one little window. As you twist the knob, the window changes color. Heck, install pin head LED's in the slider heads and lose that whole fiber optic nightmare.

...or not ;)

^^^ LOL, exactly. Reinstalling the clock I thought, WTF is this and noticed neither of the knobs for the rear A/C are lit either. Bastards... :p

legendary thread bump....

can anyone suggest who and where i can get something like this done for my 968 ?

thanks. :thumbup:

Ok, I'm pretty far along in the planning stages of doing most of the updates detailed in Ed Scherer's PDF, but I have a few questions for whoever cares to take a stab at them. I'm only planning on upgrading the main instrument cluster and the pod switches. If things go well, maybe I'll tackle the center console and other areas later.

#1) I have a 1987 S4, so obviously there are some differences in the document based on Ed's 1990, but has anyone tried this on a 1987? Do the bulbs from Super Bright LEDs more or less work and fit as they did in the 1990? Obviously the number of bulbs will be different. Since the board is definitely different, I was wondering if the holes would still need to be beveled. I have the instrument cluster all apart already (I was trying to improve the lighting reflectors and also tweak the fuel gauge which was only going to 3/4 full).

#2) Since the board is obviously completely different, the figure that shows the polarity markings won't do me any good. What is the best way to figure this out on my board? Is it as simple as putting a bulb in there and just testing it with the positive and negative power on the copper base surrounding the bulb hole? And if it works, then I know. If it doesn't reverse and it should work? Will I risk damaging anything by doing this? This sounded like the best method from what the document said, but I wanted to make sure I wasn't reading things correctly.

#3) For the pod switches (the 5 main cylinder switches on the right and left of the main cluster), I assume those are more or less the same in the 1990 and 1987. But the wire colors in mine do not match the images of Ed's 1990. So for adding the resistors, I don't have any blue wires. I believe I have 2 browns, a white and a brown/blue. At least for the main lights. Then others have more wires. Does anyone know what the correct wire to add the resistors is? And if not, how I can figure this out?

#4) For the dimmer switch, any one have any additional details on how to put this together? Or any updates on how Ed's is working out?

I think that is it for now. I know I've been thinking of questions for this post for a while. This upgrade seemed pretty intimidating for quite a while, but now that I've got everything removed and read and re-read the main post threads on reenlist and Ed's PDF several times over and over again, it doesn't seem quite so bad. Any help or advice is greatly appreciated.

-Bill

I'll help where I can.

Someone else (spikec) was just asking me about doing the upgrade on an '87 a few weeks ago. You might try PMing him and seeing how it went with his attempt.

Unfortunately, I don't have a pre-'89 to experiment with and have little knowledge of the instrument clusters on them.

I'd be happy to add pre-'89 information to the document if and when somebody completes a conversion successfully and provides me with the detailed information I'd need.

Here's what I wrote to spikec when he asked me that same question (regarding LED polarity on the instrument cluster board):

I'll try to look at this later today (evening/night); I need to check the wiring diagrams for the '87.

I do. :) I've got a final version (newer and much more bullet-proof than the one installed on my car) of the dimmer module designed and running on a breadboard. The newest design will survive all sorts of nastiness (reversed power, shorted output, etc.) It's also using a more compact, inexpensive microcontroller now (ATtiny85) than my earlier versions.

Where the dimmer module stands now: I just need to create some PC boards and get the modules assembled. I keep thinking it's just a couple of weeks away, but I'm constantly getting involved in other projects. I'll try my best to get back to this and get it done.

Keep us informed of the progress and don't hesitate to keep asking questions. I'd especially like hearing details of how your '87 is different so I can update my document accordingly.

Note that the dimmer module can be added later when it's available. Until then, your existing dimmer control just won't do much to dim your LEDs.

Wow what an awesome update. 928ntslow, I like your 'ICE' . is that a double din display? Looks right at home.

Bill -
Sorry I can't help with your 87.

The center console is easy--we just made it hard(er) by trying to light up the blower knob. If you skipped that, you'll find it's much easier than the cluster and pod switches. But like you, I wanted to do everything in stages.

Once you're addicted to LED conversion, check out this thread, specifically Ed's #40 post. He includes the rest of the body lights.
https://rennlist.com/forums/928-foru...ich-one-3.html

FWIW - I've seen in some of Rob Budd's posts that he has an off-the-shelf dimmer that he's really happy with. He mentions it in this thread, but when I go to the company's URL, their website is out of date.
https://rennlist.com/forums/928-foru...ent-bulbs.html

Yeah, I just tackled the instrument cluster first because I already had everything ripped open because I was trying to fix my fuel gauge and boost the light my instrument reflectors were putting out. Glad to hear about the center console. That one sounded the hardest to me.

I wonder if the dimmer Rob Budd mentions is something like the third on this page:
http://www.theledlight.com/dimmers.html

Thanks, Ed. I'll try to take photos as I go and pass on info on the 1987. I work at an engineering college but have been trying to not bother anyone too much with this. Worst case, could I hook up the cluster and start the car and see if the lights work that way? Then note which ones don't and then pull it back out and reverse the ones that don't? I don't think all the cluster lights go off at startup (I can't remember), but maybe that would be an option. And I'm thinking this just for the twist bulbs, not the pod bulbs. But maybe I should just wait the next few days until I get my bulbs in the mail and my questions will make more sense.

I'll post 2 images that I took of the back of the cluster. They aren't great, but I used them to map what bulbs worked of my current incandescent lights (all of them did!) and what color and type of indicator they were so I could order my best guess LEDs.

As an example of what I was talking about with looking for traces common to multiple bulbs, the yellow dots indicate some common traces. These are probably where you'd have the cathode (low/ground) side of LED bulbs. If that doesn't work, then they're all the anode (high/12V) side. IOW, the yellow dots mark either all cathode side (more likely) or all anode side (less likely) for the LED bulbs.

Attachment 621390

I just did some of this for my instrument cluster. I was planning to swap the backlights and the LCD lamps.

One thing I can tell you (although it may be elsewhere in this thread already) is that the smaller lamps in the digital dash are the B8.4D style. Superbright carries these, so you don't need to do any soldering or other customization to install these twist-lock lamps.

Anyway, two special things about my experience:

1. I also used the WLED-x5 lamps for the backlights. In order to allow these to fit through the stock holes, I had to grind down the side LEDs a bit with a drum sander on a Dremel. No harm from the sanding, though... if anything, it provides a bit of an improvement in lateral dispersion. I also found that I had to push the leads all the way to the outside, at the bottoms of the lamps, in order to get them to make contact with the contacts in the holders.

2. I bought green and red lamps for the LCD display. In the end, though, I decided to stick with the stock incandescents, as the LEDs (the cheaper/dimmer B8.4D's) while being a good brightness, still made for too much of a spotlit (i.e. uneven) backlighting of the LCD panels.

Cheers,
Paul

Paul, thanks for sharing your experience with this.

Hope you're settling on a solution that works for you.

I didn't need to do that, but in my write-up, I did mention that those WLED-WHP5 bulbs (using the original brown twist-lock sockets) are best inserted after the bulb PC board is reattached to the white plastic piece and you still need to jiggle them a little to get them inserted.

Of course, the bulbs you got might have been ever so slightly different. It seems that the manufacturing tolerances on these bulbs aren't real tight. :)

I recommended the B8.4D-AHP (amber for the four uppers) and B8.4D-RHP (red for the four lowers). Note the "HP" (high power) suffix; these are both brighter and have a more even, wider field. Believe me, I did a lot of experimenting with different products before coming up with my recommendations. :)

The B8.4D-xHP versions look like this (this happens to be a blue one; you'll want amber and red for the LCD "information display" backlighting):

https://lh4.googleusercontent.com/-R...1-05-0167a.JPG






I've already posted these photos in other threads, but a fully populated instrument cluster bulb PC board using the LED bulbs I recommend looks like this:

(Click any of these photos to see them in their full high-res glory)

https://lh5.googleusercontent.com/-m...11-05-0380.JPG

https://lh4.googleusercontent.com/-G...11-05-0383.JPG



And you'll see that it's rather nice, even lighting; the info display backlighting isn't perfectly even, but it's pretty darn good.

The photos don't quite do it justice, either. It's hard getting good photos of the cluster in the dark, and I've noticed that LEDs show some weird color shifting and brightness differences in photos that you cannot (or can barely) see in person.

https://lh4.googleusercontent.com/-i...1-05-0472a.JPG

https://lh5.googleusercontent.com/-q...1-05-0520a.JPG

https://lh5.googleusercontent.com/-a...1-05-0462a.JPG

https://lh3.googleusercontent.com/-e...1-05-0457a.JPG

droooooool....

Looks like you're using the WLED-x5HP's in that shot. The regular WLED-x5's use lensed LEDs rather than surface mount ones.

I had thought about amber, but when I shined a light through the LCD (power off) it transmitted more green, so I that's why I went with green. From your shots, I think the amber probably is a better call, though.

Thanks for sharing.

Paul

Keith:

Thanks very much for this excellent article. I've been looking for this type of info for a long time.

Barney

I am nearing the end of my dash LED conversion, and all that is left to do is the switches. I was looking for the blue/black wires on each of the switches, but I noticed that on the 4 way flasher switch there are two blue/black wires. Can I solder the resistor to either of those wires? I just want to make sure before I dive in head first. Thanks!

I'll try to remember to update the document to include that detail when I get home this evening.

I'll just quote (and bold the most relevant parts) an exchange from another thread that answers the question:

Thanks for the reply, and thanks even more for the excellent guide! I wouldn't have even attempted the conversion without it.

In the case of my two black/blue wires, they are both joined inside the switch. Short of trying to pull out the wires and re-connect them, could I just put a resistor on each wire?

You're welcome!

No... the two BK/BL wires must remain connected with no (added) resistance between them. IIRC, I cut them far enough away from the switch that it left enough to work with and then just put the resistor between each pair. Just think of it as the same wire that happens to be split into two pieces. :) After you strip enough to solder to (and remembering to put the heat shrink tubing on before soldering!), just twist each pair of two wires back together again along with the end of the resistor, e.g.

Cool, that makes sense. Now I'm gonna get out my soldering gun. I'm pretty useless when it comes to electrical stuff, so this has been a huge help. Thanks again!

Question: what bulbs does one use to replace down next to the AT shifter in earlier cars? They're different from others used throughout the car, and emit a horribly dated orange glow and I want to change them to LED.

Get the 5sp shift boot and get rid of that bit of redundancy. You have indicators in the inst. cluster for what gear your in.:thumbup:

Umm, actually I don't. haha, is my '84 supposed to have the indicators in the dash as well?

Its a bit OT in the fact its an exterior LED but what is the bulb type for replacing the reverse lights...

I know i have seen it on here some where but the search eludes me this time.

See My recommendations for exterior LED bulbs on '90 S4 (should mostly apply to '87+). I'm pretty sure that the SuperBrightLEDs 1156 LED Bulb - Single Intensity 45 SMD LED Tower that I recommend there are also the ones that I show in a post that shows a "promising LED" compared to the original incandescent bulb. FWIW, I'm still not satisfied with these; I hope to eventually find something brighter.

Still wondering if there's a replacement for the ones that light the transmission gear #s on the center console of earlier auto cars?

I'm guessing there is... but I have no idea what it is. If you can get me a good photo of the bulbs (removed from socket would be especially helpful) and sockets, I might be able to advise.

IIRC, some of the bulbs on earlier cars were soldered in.

I seem to remember some posts on this topic (bulbs in earlier cars); if anyone could link to those here, that would be nice.

My dash lights don't work, I will go with the LED lights, it really update the car !!!!

My vague memory is that the bulb used for the shifter-illumination on early cars is the same as the red safety lights in the doors; a BA9 1.2W 12V bayonet bulb.

I could be wrong - as I've never owned an early car, and I'm going just from memory of reading rennlist posts. A search here for "BA9 shifter" might answer whether I'm right.

Hi Ed,
The PDF at:
Converting Porsche 928 Interior Lighting to LEDs

seems to be corrupt or the link is broken. Is posted somewhere else?

Thanks,
Greg

Howdy, Greg.

I just tried the main link at http://www.ed.scherer.name/Porsche_9...0to%20LEDs.pdf and it was OK. What exactly are you seeing?

Anybody else having a problem with that link?

All I get is just a blank white screen. My computer recently upgraded itself to IE11 and it has been quirky. So, if you say it is there, then maybe it is one of those undocumented features of IE11. I'll play with the IE11 settings some more.

Thanks,

Greg, you could also try (in IE11) right-clicking the link and "Save As..." to a file on your computer. Then double-click that file in Windows Explorer to open it up in Adobe Reader (or whatever other PDF reader you might have established for .pdf files).

I read the initial post but not the follow-ups so this may have been discussed?

For the interior and under hood festoon bulbs it seems there are two different lengths.

Anyone know what they are and how many of each?

There are a total of 8: 2 doors, 1 overhead dome, 1 rear hatch, 1 glove box, 1 courtesy light in pax footwell (GTS) 1 overhead reading light between visors, 1 under hood light.

Thanks.

I believe the recommendations in the "Courtesy Lighting" section (near the end) of Converting Porsche 928 Interior Lighting to LEDs are all valid except the under hood bulb changed sometime after the '90 MY ('91, I think); '90 doesn't use a festoon for the under hood lamp. There's also a complication with that one. See the threads LED under hood lighting and New hood switch, strange light behaviour?. Looks like you'll need a 220 Ω load resistor in parallel with that under hood LED lamp.

Thanks, Ed - that write-up is a thing of beauty. I need to add it to the FAQ if it's not already there.

The GTS under hood light is indeed an old fashion festoon bulb. May just leave it stock for now.

In Keith's write-up he recommends a brighter bulb for the forward 'map light' located between the front visors. Did you use a different type for that one?

I'm wondering why you chose the narrow beam type for the overhead hatch, rear hatch and CEL panel locations?

Great write up Ed. Is that link to the latest version? I noticed that the Center Console and Courtesy Lighting sections just contain TOC information.

Page 41 of that doc contains those sections.

I saw that but thought perhaps he had a write-up with pics since the first page says "incomplete draft". Granted those items are just bulb replacements and the info on page 41 is what really matters.

Yes, it's the latest version. Unfortunately, I never completed those sections. Perhaps some day...

IIRC, the original interior festoon bulbs were 36mm long. However, in that length there were no really bright LED replacements. So we used the 38mm long version, which was also available in different colors. It was a bit harder to install the longer bulbs, but one could shoehorn them in without too much effort. And because they don't create as much head as the original bulbs, the fixtures never buckled.

Ed?

Sorry... just now noticed this.

I think there might have been some physical size constraint issue, but I really don't remember.

Fantastic thread.

Can someone tell me the exact placement of part #9 from this photo?

I found this picture in my folder on '78 #241 that I did last year. That washer is the shim to get the bevel gear to line up with the selector knob gear.


https://webfiles.uci.edu/redwards/pu...%207-23-19.jpg


https://webfiles.uci.edu/redwards/pu...%207-23-19.jpg

Troubleshooting on a digital dash
 

Im in the middle of this change-over on my 1992. I have all the bulbs in the gauge cluster and did a test power up. However I have two issues that I could use help with:

First, I seem lost the bright/dim toggle on the general backlighting, I am using these 194 LED Bulb - COB LED - T3.25 Miniature Wedge Base - 135 Lumens for the backlight. These are dimmable bulbs and I have used these before in my 1988 dash with success. Are others experiencing this loss of a feature when converting to LED?

https://d114hh0cykhyb0.cloudfront.ne...jpg&w=585&zc=2

Secondly, I seem lot have lost the illumination at the HVAC/radio/ashtray with the headlights/parking lights are on. Is there any continuity dependancies between the backlighting of the cluster and the accessories? The pod switches still have backlighting when the headlights are on.

The regular dimmer won't dim led bulbs. If you want dimmabiliry, you need one of Ed's LED dimmer solutions that hooks up to the regular dimmer wheel but changes the resistance or something to make.it work with LEs, but then you have to convert every bulb in the dash, cluster, and HVAC to led so the dimmer works with them.

I dont think my issue is related to the LED bulbs. I swapped them back to the original incandescent bulbs and no change. I have only one setting for backlighting, and I have no voltage going to the illumination of any of the pod switches or center console accessories. Basically I have no voltage to the Black/Blue line. So it must be unrelated to the LED swap. I'll need to research the wiring diagram to figure out where I am loosing the voltage to that system. It looks like the problem is upstream of the dimmer controller

As you troubleshoot this, make a jumper wire and connext the two wires that go to the dimmer rheostat together. That will make sure that the issue isn't the dimmer itself and the lights will all be full bright. If the lighting doesn't return when jumpering the dimmer, the problem is somewhere else.

As Petza says when you have fixed this - they still won't dim acceptably - you need a PWM solution to dim LED's like Ed's and all pod/console illumination will need to be changed to LED.

Alan

Dimming issue solved
i figured out my issue, it was a simple fuse issue (fuse 9). I must have overlooked the fuse to the dimmer when I was checking the "instrument cluster fuse".

Dimmable LED's work with the stock rheostat
The LED's I used were dimmable and they do in fact dim when using the OEM dimmer, and it retained the Bright/Dim setting when using the headlights/parking lights/ Here is a video demonstrating the dimming. The dimmable range is not very much because these LED are far too bright to begin with.

Some LEDs are too bright for the POD
I will point out these primary backlight bulbs I used are far too bright at 135 lumens. Too bright on the eyes in daytime and too bright at the lowest dimmable setting. I see light leaks through the black filament. I would NOT recommend using this bulb, I would recommend using something with about 25%-50% less lumens (75-100lumens). Something like this bulb, 194 CAN Bus LED Bulb - 5 SMD LED Tower - Miniature Wedge Base, would be 65 - 85 lumens depending on the color temp you want would be a good choice.

Some of the colored warning lights are also too bright because they are used at nigh when driving and they can be hard on the eyes. These would include the blue at 4.5-lumens (brights) and green at 15-lumens (parking, blinker, PDD), and specific red lights at 8 lumens (Parking and brake test). My solve for this the to add a piece of colored painters tape to these lights. It offers just enough opacity to dim the bulb.

Ghost Illumination
I found several warning lights will stay dimly illuminated after shutoff as long as the information bar stays illuminated. This include: ABS, "P" for automatics, and Parking Brake. I am going to revert these back to incandescent so I don't have that issue anymore.