I have been away from the group for a while but just noticed Doc has been
trying to help someone with A/C probs. and cruise probs. Had the same on my
91 Z71, A/C turned out to be the bl/w stripe wire from A/C relay to control
head not making contact at the control head connector, this is the wire that
grounds to engage relay to turn comp. clutch on and off, some contact
cleaner and a slight scrapping of the metal connector and all is well.
Cruise control runs through the brake light switch attached to the brake
pedal, my cruise wouldn't work but brake lights were fine, replaced switch
and all is working great now. Hope this helps.