I own a 1994 jeep grand cherokee Laredo and haven't had too many problems with it. However, this past winter I noticed a metal on metal grinding/zipping noise only for a quick second when first starting the vehicle and only after it had been sitting all night in cold weather. It would not make the noise when driving, only when first turning the key over. Now that summer is here and I am running my air conditioner, the problem has became much worse. Now it makes the same noise every time I start the vehicle and also any time I turn the air conditioner on. If I do not turn the a/c on it does fine. However, as soon as I turn the a/c button on it makes the grinding noise constantly (worse when first driving and accelerating/turning. It also has started squealing really bad and the power steering will lock up occasionally when the air is on as well. We changed the serpentine belt and the fan clutch, but it has not solved the problem. We are hoping to avoid having to change the entire compressor, thinking it is possibly the compressor clutch? Thank you for any assistance you can offer.
A/C CLUTCH BEARING. THIS WOULD CONSTANTLY MAKE A RACKET TILL IT LOCKED UP
A/C COMPRESSOR. THIS IS MY BEST GUESS, AS IT ONLY TURNS WHEN A/C MODES ARE ENGAGED
ANY HEAT MODE THAT USES "DEFROST" TURNS ON THE COMPRESSOR TOO. REMOVES MOISTURE FROM THE AIR BEFORE THE HEATED AIR IS BLOWN ONTO THE WINDSHIELD. THIS MIGHT ACCOUNT FOR THE WINTER NOISE
IF EITHER THE A/C COMPRESSOR OR THE CLUTCH "LOCK DOWN", EVEN TEMPORARILY. THE BELT MAY STOP MOVING AND YOU WILL LOSE ANY ITEM'S FUNCTION THAT IT TURNS. STEERING IS NOT A GOOD THING TO LOSE, ESPECIALLY AT A CRITICAL TIME!
+++++IF THE CLUTCH IS FINE+++++ UNPLUGGING THE COMPRESSOR CAN GET YOU BY---THIS ASSURES IT WILL NEVER ENGAGE AT ANY TIME. TILL YOU FIX IT. OR TILL YOU GET REALLY HOT!