FW: Electrical gremlins

[Kaasler, Ingvar]

-----Original Message-----
From: Kaasler, Ingvar 
Sent: Thursday, June 03, 2004 10:02 AM
To: 'quattro at audifans.com'
Subject: Electrical gremlins
 
            I've gotten much info and help by reading the postings in this
list. Now I'd like to pass some info along to others who may benefit.
I own a 1989 200 turbo Quattro that I restored. 
            One thing that kept me puzzled for awhile was that the #4 fuse
kept blowing randomly. This fuse powers the dash computer display, interior
lights, trunk light, and various other circuits. Trying to ignore the
problem didn't work. I finally had to start tracing the wiring to find the
fault. What I found was that the trunk light and the footwell lights had the
hot and ground connectors reversed on the lamp. What this meant is that the
supply voltage was routed onto the long metal clip that runs along the bulb
to the back end of the bulb. This caused random shorts to ground whenever
this metal clip touched the body of the car. After checking and correcting
the wiring connections to all the lamps I haven't had any more problems with
fuse #4 since the last four months. Below is how the connectors should be
attached. Hope this helps someone.
 
 
             _______________________
Gnd  ----|                                        |
                    _________________   |
12v   --------|/       bulb                  \  |
                   \_________________/  | 
 
 
Ingvar K.