I have a number of jobs I want to do on my instrument pod, including cleaning the gauge terminals (jumpy fuel needle!), replacing dim illumination bulbs, replacing non-working auto bulbs (D of course, but will do R while I'm in there!).

All my warning bulbs work correctly, but I may change all the 1.2W bulbs if they have dimmed with age.

The warning bulbs are in push fit sockets. On the PET the bulbs are separate from sockets.

My question is it is possible to take the tiny 1.2W bulb out of each socket - how? If not do I have to buy all the 19 bases as well as the bulbs?

Thanks

 

Try this: (page 2)

https://rennlist.com/forums/928-forum/372301-15-minute-instrument-pod-removal-update-and-instrument-light-bulbs-for-an-ok-price.html

Let me know how you get on as this is on my to do list!

 

Wow, I didn't find that write-up when I did mine. That's great stuff.

For the bulbs, get the ones in the socket. Soldering those little buggers is a royal PITA. I forget which vendor has them in the holders already, but it's worth whatever they charge. I got the bulbs separately and it was too much of a hassle to replace them all, so I've now had the pod apart several times to do them as they burn out, and replaced just the one that was out.


Here was my write-up:
https://rennlist.com/forums/showthre...ferrerid=45339

 

I would not replace them all. Replace only the ones that gets lots of use and age. All these that are on continually are run at below max voltage => they should last a long time! They also won't dim with age unless they are actually on - this happens due to sublimation of the filament to a gas and deporition on the inside of the glass bulb. For the warning bulbs that rarely see use this means they should be fine.

I'm all for PM - WYAIT etc but I would not change them all.

Change: turn signals, High Beam, D, P, 2, 1 (depending on how you drive) the Stop light warning, any other warnings you get a lot (TPMS?)....

Despite what PET may show - the warning bulbs are usually manufacturing compression/crimp fit - tough to resolder a new lamp in - just not worth the hassle. Just buy the replacements.

For the main dash illum you may have more luck just replugging for the later style analog & digi dash they are regular wedge bulbs in sockets. (maybe thats what you saw in PET?)

Alan

 

The 1.2w bulbs in the push-twist socket are ~$1 each at 928 Specialists. Why bother attempting to do it the hard way?

 

Yes my S4 is very late analog (1988) and the illumination bulbs are 3 3W bulbs along bottom of pod. They are wedge base and just pull out so I'll change these and also check the plastic in front of them.

So from what people have said it sounds like the 1.2W don't just pull out of the warning bulb sockets, but are crimped in? In that case I need to buy bases as well as the bulbs.

 

This is interesting.

First off I picked up a very cheap pod on eBay to practice on before I pull mine (it was from a LHD car so no-one else in UK wanted it!).

The 1.2W warning bulbs are held in their plastic holder by tiny metal barbs. If you depress those the bulb and its metal contacts come out. The wires of the bulb are soldered/pressed onto the metal contacts.

The 91 PET looks different. If you just bought the bulbs (from Porsche or elsewhere) then it would be incredibly fiddly to replace the old bulbs. But again from the PET it looks like you can't buy the bulb and its plastic push/twist holder as a complete unit from Porsche. So how have other people replaced the style of bulb I've photographed below?

 

I don't see these listed currently on their site - just the 3W illumination bulbs.

Will have a look around auto bulb suppliers in the UK to see if anyone is offering replacements in the sockets.

 

Have looked at 928 International who list the 1.2W bulbs in blue push fit holder (928 641 982 04, for 89-95) which looks like it would just replace the separate bulb/holder shown in the 91 PET. 928 International shows the separate bulbs for 88 cars and as others here have noted life is too short to try to put them in the old sockets!

Can anyone confirm that the push fit holders for an 89- pod would fit in an 88?

 

I forget where I got the bulbs I ordered, but the ones I got were just the bulb shown in that pic with the metal leads coming out. They didn't have the metal push-in connectors. I had to cut the metal tabs off of the dead bulbs and solder the new leads onto it (making sure no solder was left to obstruct the 'push in' action).
Stupid, I know, but I ordered them thinking I was getting the whole thing and then I had the pod out and opened the box to find that. More work than it's worth, but at least the lights are all working properly now.

 

I just, a few weeks ago, replaced all the bulbs in an '89's digital cluster. A while ago I replaced a bunch of bulbs in an '87 and an '85. But, those memories a bit dim.

I think you are making this wAAy too hard. The sockets twist 90-degrees and then pull straight out of the back-side of the pod with the bulb in place.

There are some differences in the cluster bulbs between the model years. Some of the bulbs are replaceable once you twist the socket out. Some are not. IIRC. If you have to use anything other than your fingers you're not going about it the right way. (Or on the '89+ a 6mm IIRC socket to help twist the bulb socket out...) Then you can replace the bulb if its the replacable-without-a-socket type. The '87-88s have the replacable bulbs. The '89+ needs the bulb-in-a-socket type.

See PET 906-00 for '87-88. There are part numbers for the sockets and numbers for the bulbs. 906-01 shows the bulb-in-socket type for the '89+.

Call them. Their web site isn't up-to-date on the bulb-in-socket parts.

 

I don't recall now if the '87 bulbs were removable or not. I *think* they may have arrived as bulb-in-socket assemblies. I do recall that replacement of the bulbs took about 5 minutes total for the whole display.

 

Thanks for all the advice.

I realise the bulb assemblies just twist and pull out - I just took one apart to see if the bulb is easily replaceable (it isn't, though another poster here was dextrous enough to solder new ones to the old tabs).

In fact I took all the assemblies out just so I could quickly test them. On a pod covered in Sep 86 labels (I'm experimenting on an old pod sourced from eBay), every warning bulb and illumination bulb still worked fine! Only the illumination bulbs were a little faded on the glass envelope (the prisms look pretty clear). The illumination bulbs are easily replaced, all the other 1.2W ones are not.

No biggie as all my warning bulbs illuminate. I think I'll just replace the illuminanation bulbs which are dim on my '88.

The other issue I've come across is the pcb which carries the PRND32 bulbs. I couldn't see how to remove this entirely from the tacho (though you can take off the tacho surround which helps access). That means you can only desolder the bulbs from one side rather than desoldering from the other side and pulling them out. Makes it look very tricky indeed to replace those bulbs! My 'D' bulb is out but again I may leave it given the risk of damaging something.

 

Ah. You were just doing it the hard way to see how hard it was?

No autos here. And the '89+ uses the same twist-and-pull bulbs for PRNDL as for the warning lights. So, I've no advice for those bulbs. However, Earl and Gary do:

http://928oc.org/journal/atlites1.pdf

 

As mentioned in Schocki's write up; the 1.2w bulbs complete with plastic socket conform to the B8.4d standard.
Just buy B8.4Ds anywhere & they screww straight in. I replaced all mine last week; actually I bought 1.5W bulbs - bit brighter.
I also replaced the 3 3W illumination bulbs with Blue LEDs from Nicole; for fotos look at
https://rennlist.com/forums/showthre...67#post4899467


Marton