Hello,
Bought a 97 grand prix 68k all stock 2 months ago. The havc control did not work but it was no biggy at the time. It seems to be in a bi-lev postion with some defrost in it so its been ok to drive. Bought my chilton and was supprised to not find much for troubleshooting this in there except for replacing the control and checking fuses. I have went through the fuses with no problem and then traced the wires to the relay. The only way i have to check this is with my 12v supply a fused jumper and listen for the clicks. Everythings clicking. I have located my control servos and they look to be ok and i cant see all those going bad so thaty is where i am at.
I have heard of checking a vacum hose?
I know how to use a volt meter and can find any component on the car i am just looking for the next step in trouble shooting. Theres not a whole lot to this particular subsystem but i have to admit im stumped.
Has Power relay ok....
Thanks