Cruise control turns off when Rear window Defrost is turned on

[fastscirocco]

I would go back to place that replaced rear window and report to them what is going on.

I did call them, only person that was there to talk to was the receptionist.
I will report back any new info.

 

[rrosen]

I'll give you a history of my cruise control mysteriously turning off. Probably doesn't apply but ....

Cruise control kept turning itself off. Dealer first said there was a chafed wire by the emergency brake that did it. Fixed the wire but the problem still existed. Dealer had car for almost 3 weeks (maybe longer, it was some time ago). Called in the GM engineers. Eventually they replaced...the radio amplifier!?!?!?!?

Apparently the amp was putting spurious signals on one of the busses (CAN bus maybe?) that caused the cruise control to turn off.

Just a data point for what it's worth.