problems with cruise control and diff lock

[Anton Greil]

Hi,

I am new on this list and I have a problem with the diff lock and the
cruise control of my ´88 Audi 100 quattro (I think this model was
available in 1989 in US). Both does not work. I checked the fuses and
the cable connections (optically) and they seem to be ok. I cleaned the
cable connectors and used some contact spray. Further I removed the
aftermarket car stereo, because I thought there was a problem with the
vehicle speed signal. But all did not work. Now my question: Could it be
that the cruise control and diff lock are dependent on the gear unit
because it was replaced after a transmission failure some time ago. (But
both worked after changing.) What else could it be?

thanks
Toni