928ntslow

Ed...got the removal process down to around 15 minutes as well...lol, been timing it to keep my sanity. Install is a bit trickier, but 20 minutes seems to be the number. I opted to leave all the very rarely used indicator lights as is...just didn't seem worth while to change everything. Yours looks great...not sure if this last pic of the lit cluster is with the dimmer as it does look dimmed. That was another thing I neglected to do as the illumination seems perfect for me and non distracting. To each his own I guess.

I will get back at the troubleshooting today or tomorrow.

Thanks Stan, I had planned on methodically going through the process you had mentioned. Thanks for the tip on the spare tire well, but I would be very surprised if that was an issue there.

Ed Scherer

Thanks, Stan. That raises the probability that the turn signal indicator bulb really is driven with opposite polarities at different times.

Given that the incandescent turn signal indicator bulb doesn't light when the turn signal is used in "parking/marking" mode (with ignition switch in "0" position), it looks like the only thing you lose by using a polarized LED turn signal indicator bulb is that it won't blink (as the incandescent one would) when the ignition switch is in position "0" and the hazard lights are on and blinking. This seems extremely minor to me (since the huge red hazard switch backlighting bulb is blinking away) and not worth addressing.

I think I'll just note this minor behavioral change in my document and leave it at that.

Actually, I didn't have my PWM dimmer installed at that time.

In full darkness with the LED instrument lighting at full brightness, it's just too bright, IMHO; so bright that you can actually see a bit of light bleeding through some of the black-masked areas (like the speedo/tach areas) a bit. And (again, IMHO) just a bit overpowering and distracting. Bottom line is that it's nice to be able to adjust it.

You really can't draw any brightness conclusions from these kinds of photos, though. There's a huge variation in light intensities in these scenes and it's a challenge to get acceptable photos with the limited dynamic range of most cameras. FWIW, I discovered that for such photos, you're best off going full manual on your camera (and shooting RAW, of course) and going for an exposure that assures that the details on the bright items (backlit pod ***** with symbols, backlit/labeled indicator lights in the cluster, etc.) aren't blown out. Then you can play with the resulting image in your favorite RAW processor and tweak it to restore the details in the darker areas.

borland

Ed,

When you put the left or right lights on with the turn signal toggle, what actually lights is the 'marker lamps', not the turn signal lamps. So you wouldn't expect the green indicator light to come on. I know this is not intuitive, but the wiring diagram shows this as well. You must have your lamps painted over in red.

Another source for the problem might be the flasher (LED flasher too). I don't remember if the green lamp flashes in sync with the turn signals with the factory flasher?

928ntslow

True...when parked, and the key out of the barrel, all lights off...moving the turn signal stalk left or right activates the relative side of the vehicles parking lights, not turn signals. I believe the wiring diagram shows the re-routing of the circuit to the parking lights, not the turn signals...plus you will not see an indicator light on the cluster...you will just hear the tone module when the driver door is open...not sure about the other doors.

As for the turn signal lights blinking out of sequence with the indicator light, we can thank the relay for that. I don't know the specifics, but the relay works off of resistance which shuts the current flow path down when it reaches its peak resistance each time...about twice a second. At that point, when the relay shuts down, the indicator light illuminates...almost as a backwash of current. This may be incorrect, but that the way I think it is. Of course, this is when the key is turned to anything but "0".

I think when the Hazard switch is engaged, the indicator light flashes in sequence with the exterior lights (when the key is out of the barrel), because the current flow is then re-routed to the indicator light from the backside of the relay. So its getting the same current flow as the exterior lights. Again, I could be incorrect on all of this.

As for my non illuminating LED bulb, I am beginning to think it is 180 degrees out of polarity. It's been so long since I worked on this, that I forgot what I actually did to make it work.

Ed Scherer

Um... yeah. You're right. I'll go back and fix those posts so they don't contain misleading info. I'm not sure why I thought that; I guess I never paid enough attention to what was really lighting up for that mode. I actually have used that feature before—quite awhile ago, though—when parking on a street, and worried a lot less about battery drain given that it was relatively low-current LEDs lighting up.

Thanks for pointing this out. I really dislike spreading incorrect information.

I'm pretty sure it's out of sync. Perhaps someone else (still using the old-school incandescent bulbs) can verify this.

Yup. I think we can all agree on that; I got that detail wrong.

Turn signal indicator lights blinking out of phase with the turn signals is very common thing with 3 terminal relays. Here's a simplfied diagram of a typical circuit (much simpler than what's in our cars, but I believe most of the same principles apply):



If you study that for awhile, you'll probably also see why load resistor(s) are required to get the turn signal indicator light to illuminate after you've converted the turn signals to LEDs.

I think you're thinking what I'm thinking.

928ntslow

Yep...that was it. Bulb had the polarity reversed. I just flipped it 180d and low and behold, turn signal/flasher indicator light now works. I tell ya...3+ years down the road not working on something, you turn back into a newbie. What a rookie move. I must have been testing from the wrong ground with the cluster out.

Thanks for the help! Now onto the brake sensor circuit.....

Ed Scherer

Time for...

And, BTW, based on my findings, I don't think you can test that bulb (when it's an LED) by providing 12 V to the turn signal terminal at the cluster and ground at the cluster... it works the opposite way. You'd need to put ground on the cluster turn signal terminal and 12 V somewhere else on the cluster (it's got multiple power supply terminals and I'm not sure which one is "the one" for that LED).

Obviously—armed with the insight you gained from the previous success and knowing all about how to apply the principle of generalization—you just need to flip the brake pads around.

Good luck on the brake pad service circuit. Did you check the brake pad sensor terminals at the cluster loom-side connectors when you had the cluster out? I remember seeing at least one thread recently where someone mentioned that he had a bad contact in his (possibly from bending it more than normal by inserting a DMM probe into it). It might had been a good opportunity to check the continuity from the loom-side connectors at the cluster to T23.



On a completely separate topic, that's a great photo in your signature. Of course, you've got great subject material. Fantastic wheel choice for a 928. IMHO, 928 wheels with convex surfaces on the exterior side of the spokes are a good stylistic match with the rest of the car.

928ntslow

Oh geez...don't tell me that. I'll pretend I never saw this...

I just found T23...among other things. What I thought was the T23 connector was the PO's work of a plug disconnection of the RDK with a jumper. Nice job, but took me a few minutes to figure it out. T23 is located up above the ABS unit(?) mounted at the outside wall. You have to remove the ABS to get to it as it is connected to the top of the ABS mounting bracket. It has a child proof connector that appeared to be nothing short of a Rubic's Cube. There is a sliding lock which pulls out...ribbed and located on the side end of the connector...what a PITA figuring that one out! Had to do it on my back, head under the dash by the pedals and legs up on the seat back rest. (gettin' too old for this ****). Located the wires...will get a fresh start tomorrow.

Also helps to clear the brake calipers!

Thanks Ed

928ntslow

Did the process of elimination. I jumpered pins 15 and 16 at T23 on the sensor side to have a loop to work with. RR to RF and RF to LF made contact, but oddly enough LF to LR and LR to RR did not contact. You'd think there would be just one break. I checked the spare tire well and found no connectors as stated in the wiring diagram. So I got under the rear of the car to see if there was a connection underneath somewhere, though I knew there wasn't. Followed the loom to the LR wheel and couldn't believe what I saw. (SEE PIC BELOW) Can't for the life of me figure how this could happen. It's was tight in all of the loom stays, far away enough from the resonator and the tire. I cut the exterior insulation of the loom and repaired by soldering the wires back together with splices and heat shrink. Checked and no more fault.

Thanks for the help gentleman. I hate having to fix things, hate/love fixing things, love when things are fixed!

BTW, the comment I made in post #19 was incorrect and should have been a sign that I had the LED bulb 180d out. The turn signal indicator should NOT flash when the key is in the "0" position or out of the barrel when the Hazard button is engaged... only the button itself should be lit.

Bill Ball

Good to hear this Keith. One clarification...the extra connection blocks in the spare tire well for the rear brake pad sensors and in the engine compartment for the sensorws only applies to 89 and earlier. This was eliminated in 90. That's why you didn't find any. I mentioned this and other differences between pre-90 and later cars in my earlier post.

928ntslow

Sorry I missed it...was probably too focused on the location of T23. Thanks Bill. I know you've been through these car more than I have over the years. It really has been a while since I did some real work on a 928.

Mrmerlin

so the tire was what caused this damage??
Glad you got it fixed

928ntslow

No..there is no possible way the tire could have done this. The damage was too far in from the tire/wheel and too high from the exhaust. Loom was well secured in the stays. Really have no idea how this could have happened. looks like the something a tire would do, but it certainly wasn't the reason this happened. Strange...but yea, fixed and working.