[Vwdiesel] 1989 Diesel Jetta door alarm mystery

[Doyt W. Echelberger]

Yes Eric, that sounds like good engineering and the way things should work. 
And thanks to the list for your replies.
I'm gonna change the subject line, in the unlikely case that anyone will 
ever have a similar problem with their door alarm

Eric mentioned the ignition switch as a possible cause of the unusual alarm 
function....the PO told me the car has a new ignition switch, because he 
had to jiggle the key sometimes to get it to connect and start. And with a 
new ignition switch, the really loud door alarm sounds whenever I open the 
door, even if the key is in my pocket. So, Initially I just pulled the 
relay and stopped the sound.

After reading the replies of listees, I'm beginning to think that pulling 
the relay may be just covering up another problem. Makes me suspicious of a 
faulty wiring circuit somewhere. This car was custom-wired to connect like 
a trailer to a motor home, so that the functions of the motor home tail 
lights would be duplicated by the Jetta's tail lights.

And on top of that, the Jetta has a small trailer hitch and the tail lights 
are wired to allow the Jetta to serve as a towing vehicle and send its tail 
light signals to the little trailer behind it.

I'm beginning to realize that this whole nightmarishly complex system will 
have to be superimposed on a factory wiring diagram in order to get an 
intellectual handle on the peculiar functioning of the driver door alarm. 
And then it would take an astute electrical engineering background to spot 
any flaw in the design.

I'm thinking it might be more practical to just physically follow the wires 
that are at the front of the car, which were there to connect it with the 
motor home. Then I'll interrupt the point where they connect with the Jetta 
electrical system, and effectively take them out of the equation. If the 
behavior of the door alarm changes, I'll know that the motor home 
connection was at fault. I'm not going to tow it behind my motor home, 
because my motor home is a 1976 VW Campmobile.

If the door alarm function stays the same, after taking out the motor home 
circuit, I'll trace the  wiring of the trailer-pig tail and disconnect it 
also. And if that doesn't affect the door alarm, I'll open a cold one and 
fugidaboudit all for a while.

And.... the PO is probably busy rewiring his new Focus the same way. Oh well.

Doyt
 >>>>>>>>>>>>>>>>>>>>>
At 10:39 PM 6/11/2010, you wrote:
>But shouldn't it only be beeping if the door is open and the keys are
>still in the ignition? That's the way my A1 is, anyway. It's hard to
>tell from what Doyt said what exactly is going on. If it's constantly
>beeping then try jiggling around the switch, sometimes the little
>lever thing that lets it know that a key is in can get stuck in the up
>position.
>
>Erik