ON MANY NEWER CARS, THE A/C AND THE HEATER (USING A SETTING WITH DEFROST MODE) TURNS ON THE A/C CLUTCH, THUS TURNING TURNING THE COMPRESSOR.

OF COURSE THE A/C SETTING WOULD COOL THE INTERIOR OF THE VEHICLE. THE DEFROST USES THE EVAPORATOR TO REMOVE MOISTURE FROM THE HEATED AIR BLOWING ONTO THE WINDSHIELD, DEFROSTING IS FASTER THAN IT USED TO BE IN OLDER CARS.

IF USING A HEATER SETTING THAT DOES NOT USE DEFROST, SEEMS TO GIVE NO PROBLEMS, THIS MIGHT LET YOU POINT YOUR FINGER TOWARD A BAD A/C COMPRESSOR

IT MAY BE THAT EITHER THE A/C COMPRESSOR IS LOCKING UP (REPLACE) OR THE A/C CLUTCH MAY BE GOING BAD (REPLACE)

REMOVING YOUR BELT AND TURNING ALL PULLEYS WITH YOUR FINGERS MAY ALSO FIND ANOTHER PULLEY NOT TURNING FREELY

THE INNER CENTER PORTION OF THE A/C PULLEY IS PART OF THE A/C CLUTCH---NOT ONLY TURN THE PULLEY, BUT SEE IF THE INNER PART WILL TURN TOO, IF IT DOESN'T, THE COMPRESSOR IS MOST LIKELY BAD

KEEP US POSTED

THE MEDIC

Answered by CJ MEDEVAC (expert)
6,802 answers provided