Hi guys just purchased a 1998 GMC JIMMY 115000kms on the clock, and everytime I switch on the windshield defroster there is no heat coming through because the A/c compressor turns on. Then when I turn the knob to dash vents compressor shuts down and normal heat blows out. The A/C works great when in it's position. So can anyone help me figure out why the A/C compressor turns on when I turn the knob to defrost ?
- posted
19 years ago