Help, wiring gurus needed

Mike Arman armanmik at
Tue Apr 12 09:43:01 EDT 2005

>J3 <t9j3 at>
>Subject: Help, wiring gurus needed
>Calling all wiring techs, I have a question about a wiring problem that 
>was conducted to my car at the garage the yesterday. Without going into 
>details about why or pointing fingers, I am wondering if what they did was 
>theoretically correct or wrong.

I think I'm ready to point some fingers - at them. If this were my car, I'd 
be pointing more than fingers, too.

>My 95 S6 went into a garage to get inspected and upon finishing the state 
>inspection; they noticed the license plate lights were out. They checked 
>the fuses and found that the fuses kept blowing upon replacement of the 
>fuse. The mechanic called me and told me that he could fix the license 
>plate lamps by wiring the license plate lamps to the left tail light, 
>which would bypass the shorted wire and turn on the license plate lights 
>when the tail lights were turned on.

This is usually a problem in the trunk hinge area. The wires from the 
license plate lights (along with some other wires) go down the driver's 
side support tube, and from opening and closing the trunk lid, the 
insulation gets worn where they exit the tube. Eventually, the wires short 
to ground, blowing the fuse.

>So they tee'd off a power wire from the left tail light and connected it 
>to the license plate light. After putting the positive wire back on the 
>battery and starting the car to check the lights, the dash begins to 
>smoke. They immediately rip the positive cable off the battery and wait 
>for me to arrive. Of course I wasn't there to witness the smoke fest, so 
>the details about when and how the smoke arrived is information coming 
>from garage.

No no no no no. You CANNOT kludge the electrical systems of newer cars like 
this. In the bad old days, like with a 1956 Oldsmobile or similar, this 
will work. Nowadays this is an invitation to disaster. This is especially 
dangerous to cars with electronic controls, computer controlled lights, 
and/or bulb-out warning devices (like your car).

>After this point nothing happens to the car in that garage and I flatbed 
>the car to my house.

Best move so far.

>  The next day I tear the instrument cluster out of the car and notice 
> three wires severely burned behind the IC. Those three wires had enough 
> damage to damage the instrument cluster that was directly above those 
> wires. One of the three wires was connected to the engine check light and 
> 2 wires were connected to the oil temp gauge. I then check out the 
> license plate lamp area and we notice that they connected the new wire 
> from the left tail light, but they never disconnected the older "shorted" 
> wire. So the license plate light had the new wire source and the older 
> one connected to it.

Sounds like the power from the new wire went right to the short to ground 
at the trunk lid on the old wire.

To start, remove the "new" wire and strangle the so-called "mechanic" with 
it. This guy is NOT your friend, and has NOT done you any favors.

Next, fix the short to ground. Get the license plate lights working 
properly again.

Start working forward from where Mr. Moron spliced the wire into the tail 
light wire. You'll find the bulb-out controller on the left side of the 
trunk, forward of the trunk hinge. This works by comparing the loads 
between the right and left tail lights, and if they are different, it sends 
a signal to the information center. Obviously, if the loads are one tail 
light on one side, and one tail light PLUS the license plate lights (and a 
good, solid short to ground) on the other, the light control unit is going 
to be very unhappy, and complain to the bulb-out indicator in the dash.

The fact that he connected this wire in the first place tells me that he is 
totally ignorant of the systems in this car - if he knew anything about 
Audi he would have known about the light control unit, and would have known 
that adding the load for the license plate lights to EITHER of the tail 
lights would NOT work, and that it would promptly blow up in his face, 
expensively - and guess what - it did.

>So, my question is, if they did not disconnect the older shorted wire from 
>the license plate lamp, would it have caused the short to blow up the IC? 
>It seems that by keeping the shorted wire in the circuit that it made 
>power go directly through the license plate lamp and directly to the older 

Exactly correct.

>They are saying that I am to blame because I hooked up my Valentine 1 
>radar detector and dash display that day before and that shorted the car. 
>The V1 dash display was already installed in the car when i bought it but 
>it didn't have the power hooked up to it. The V1 and V1 dash display still 
>work, when hooked up even after the damage. All I know is that the car 
>drove fine with the V1 hooked up for a day before I brought it there.

Wrong - they are scared that someone, somewhere will know more about this 
than they do (not a big trick, on the face of the evidence), and will show 
them that they screwed up (and they DID, big time), and THEY are going to 
have to pay to fix this. It is always much easier and WAY cheaper to blame 
the customer in situations like this. They are doing creative blame 
shifting - they are desperately trying to cover their sorry behinds, 
because at the very first wisp of smoke they KNEW they had screwed up - I 
notice there was no smoke until THEY "fixed" it . . . cause and effect, anyone?

>If I can prove that they made a mistake on the wiring than their insurance 
>will cover it. But if I can't prove to them that this wiring mistake by 
>them was wrong, than I guess it goes into a big legal battle. Anyways this 
>will be a big mess for some time to come.
>I have detailed photos of the wires and IC that I can email to anybody 
>directly if this will help describe the wires better.

Get some pictures of their "fix" for this mess, get some pictures of the 
short to ground at the trunk lid hinge, and take some of the comments about 
this you are SURE top get from other members of this list.

You will probably not need a light control unit (they are cheap, at least 
by comparison to other Audi electrical parts prices), but you may very well 
need an instrument cluster. If the cluster on the 95 S6 is anything like 
the cluster on my V8Q (and it is probably even MORE complicated), there are 
more transistors and ICs in it than in a color TV, and NO parts are 
available separately, period. You'll probably need the replacement cluster, 
and remember the odometer setting has to match. If you don't replace the 
cluster, it may fail in strange, wonderful and unpredictable ways some time 
from now, and then you'll have no recourse - it will be too late.

They are about to find out how much Audi parts sell for at retail at the 
Audi dealer - and this is going to put a BIG dent in their profits this 
quarter. Once you get the big check, however, you'll be buying the parts 
used from various other listers and list vendors, and the (substantial) 
difference will go into your pocket as compensation for your aggravation 
caused 1,000% by their incompetence.

Best Regards,

Mike Arman

Who *does* know something about electrical systems - references on request.

>Any help would be greatly appreciated.

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