Cruise Control Problems

[Huw Powell]

> Wondering if anyone has BTDT w/ cruise control problems on a '91 Avant.
> I've checked fuses, tested the throttle servo w/ vacuum, tested the
> brake and clutch switches to ensure they hold vacuum and dump vacuum
> when depressed. 

Check their resistance as well.  Ditto the "set" etc. switches.

> I teed the line from the pump and it makes slight
> vacuum when setting cruise or hitting resume, but not much. 

Tired pump?  Small leak somewhere in lines?

So it does work electrically?  Just unable to get to or hold a speed?

> I'd go
> through the test procedure in the Bentley book, but I can't even find
> the damn cruise ECU control unit

They are usually behind the radio, sort of.  And I've never seen one go 
bad...

This might help a bit:

http://www.humanspeakers.com/audi/cruise.htm

-- 
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/