I have researched various posts about the OBC window backlight.
I can barely read my numbers. So I took the tach out (had to remove steering wheel and air bag) and found 4 bulbs (3 in top row and one below), all bulbs check out fine. Am I missing something here??
Your help is greatly appreciated. I have tried to buy a shop manual from MY-Porsche and have been told that Porsche has them on back order until some time in January.
Thanks!!

 

Have you checked the dimmer switch? Sorry if it seems obvious...

[quote]Originally posted by Blizzard:
<strong>I have researched various posts about the OBC window backlight.
I can barely read my numbers. So I took the tach out (had to remove steering wheel and air bag) and found 4 bulbs (3 in top row and one below), all bulbs check out fine. Am I missing something here??
Your help is greatly appreciated. I have tried to buy a shop manual from MY-Porsche and have been told that Porsche has them on back order until some time in January.
Thanks!!</strong><hr></blockquote>

 

I have checked the dimmer switch and it has no affect on it whatsoever.
Was I looking at the right bulb? It appears to be the single bulb below the upper 3.

 

I believe the readout on the OBC is actually LED segments, as on a digital clock, and has nothing to do with the bulbs in the tach. When I got my C4, one of the segments was burned out and the dealer replaced the tach under Porsche's certified warranty. I'm not an electrical engineer, but it could be a problem on the circuit board and the solution may be to just replace the tach.

Vic
95 C4

 

Paul

I have recently repaired the backlighting in my OBC the issue is definitely the bulb.The segments are not the issue as long as you can see the digits although they will be very pale green with no backlight.If the bulb itself is OK you have a problem with the circuit - there is no seperate fuse so that is not the issue.It is either the wiring or the bulb holder not making contact.Try swopping the bulb holder.

 

I have exactly the same problem. With perfect instructions from Tim, I managed to change the lower bulb which I got from Gert. However, on reconnnecting the battery the OBC did not light up??????

Please let me know if you make any headway.

Sandman

 

Sandman/Paul

Sorry you seem to be struggling with this. Have you tried seeing if the bulb works with the Tach out of the dash so you can fiddle with the bulb holder or wiring to see if you have a bad contact?
Or indeed investigate a bit further using a multimeter.

 

Thanks again Tim

Will try it out.

Sandman

 

Thought I'd resurrect this thread since I've had 2 bulbs go out in the span of several weeks. Before I pull the steering wheel, I'd like to go get recommended parts.

Anyone have a suggestion as to why the bulbs would fail so quickly. Is there a circuit board that needs attention (don't believe there's a fuse, based on previous posts)?

I too am waiting for shop manuals to come available. I've got an old scan of a manual that doesn't cover the topic.

Please help! Thanks.