Speedometer Problem

[Huw Powell]

>> Sometime back, my car started exhibiting an intermittent 'stuck 
>> speedometer'.  It would just stay at zero when being driven.  If I
>>  banged on the dashboard, or even sometimes if I drove over a bump,
>> it would immediately come to life and work again.
>> 
>> I've seen, on somebody's website, that this is a known problem with
>>  some Audis of my vintage/model (Audi 100, 1990).  The problem is
>> often a bad soldier/bad connection on the circiut board.  The fix
>> is to remove the dashboard and re-soldier.
>> 
>> Because I don't relish the idea of that adventure, including
>> removal of the steering wheel, I'd first like to get opinions on
>> whether something else, possibly more simple to correct, might in
>> fact be the trouble.
>> 
>> Don't know if this adds to the info, but when the speedometer cuts
>>  out, the cruise control also shuts off.

> You've managed to ferret out the most common culprit - unless you do 
> the repair and rule that out, then we're just spitballing (maybe
> check the wiring diagrams to see where there's a common connection
> between the cruise and the speedometer?....splat!).  While you have
> the dash out, it might be a good time to make sure all the lights are
> working.

I think biting the bullet and pulling the cluster will be the most 
effective use of your time.  First you might want to see if anyone has 
photographed or at least described the fix on a web site.  Chris 
Miller's might be a good place to start, or perhaps the audifans KB.

http://members.aol.com/c1j1miller/main.html

http://www.audifans.com/twiki/bin/view/Audi/WebHome

The cruise not working is just telling you something you already know - 
that the speedo is not working.  One input the cruise system uses and of 
course needs is "how fast is the car going."  It gets this from the 
speedometer.

Your speedo is electronic.  There is a sender at the tranny (upper 
driver side, I think, but I may be totally wrong), and it pretty much 
goes straight to the speedo where the signal is converted back to a 
physical action.

-- 
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/