strange electrical problem, revisited

["Rob Reesor" <reesor@tss.com>]

The other day I posted some info regarding a strange electrical problem that
I've been having with my '81 Coupe. Not only does the problem persist, but it's
getting worse. Here's the latest particulars. Any ideas would be greatly
appreciated.

Driving along, minding my own business, and suddenly the engine dies. This is a
particular treat in Bay Area rush-hour traffic. All electricals that are not
directly wired to the battery are dead. This means that I have only hazard
lights, parking lights, and radio working. All dash lights (e.g., ignition,
seat belts, etc) that typically light when the key is turned to the accessory
position are dead. The engine turns over but will not start since there is no
voltage to the coil. So, I run a wire between +12 and the coil. Now the lights
on the dash come on and the car starts and runs fine. If I disconnect the wire,
sometimes the car will continue running, but most the time it dies again.

Anyway, this scenario played out twice yesterday. Now the car will only start
and run if the jumper wire is attached. Also, when the wire is attached and the
car is running, I can turn off and remove the key and the engine just keeps on
running (not dieseling, mind you, but really running).

This kind of problem is beyond my abilities. And so far, unfortunately, beyond
the abilities of my favorite (and typically quite able) Audi mechanic.

To summarize the symptoms:

1) Car dies arbitrarily due to lack of voltage to the coil.
2) When this happens, the coil is dead, as are all accessory lights.
3) Engine will start with a jumper between +12 and coil (post labeled 15)
4) When the jumper is removed, the engine dies again.

I don't believe this is the voltage reduction relay as that reduces voltage to
accessories but not to the coil. I expect that there's a problem with a relay
somewhere, but can't imaging where.

Any thoughts?

Thanks,
Rob

-- 
+-----------------------+-------------------------------+
| Rob Reesor            | Teknekron Software Systems    |
| reesor@tss.com        | 530 Lytton Ave., Ste 301      |
| 415/617-2217          | Palo Alto, CA  94301          |
+-----------------------+-------------------------------+