I replaced my a/c compressor with a new one. Took it to my mechanic to have it vacuumed and recharged. After I got it back, That schreeching noise was still there---By the way the A/C works like it did when I first bought my jeep over a decade ago. Well he told me the noise was the idler pulley. Doesn't look like a hard fix. They run cheap enough to try anyways...I do have my belt tight and lubed by the way.

 

mine did the same thing a while ago, turns out, i was low on refrigerant oil. there is a certain number of ounces that need to be in the system. could be the same problem?

 

My belt is pretty worn and I will need to change it soon. I will be needing INSTRUCTIONS ON HOW TO INSTALL THE BELT fellas. I sprayed w-40 for now and the noise is gone. Thanks.

 

that noise is from your vents my 92 does that sometimes also, sounds like a creature dying lol

 

It's the same as tightening the belt except you back off the tensioner first enough to slip the old belt off. Slip the new one on and tighten.

 

I think a belt routing diagram is what be needed..

 

I had the same issue. It would make that noise only on low, then it finally died on me. Autozone has the blower motor for like $26 and rockauto has the relay for $7.

As one person said determine where the noise is coming from. Outside or inside. If outside your lookin at the belt/bearing. If inside the blower motor /resistor/relay issue.

I would start with basic free stuff that can help narrow it down before blowing any $$ on parts you don't need.

Good luck!

 

I am having the same screeching sound...I replaced compressor also (HVAC guy is me), wasn't that either. Replaced the belt, still noise. Replaced the tensioner pulley, guess what? Not the problem. I have now diagnosed the power steering pump is going bad. The noise becomes present when I turn the AC on, goes away after a few moments and some throttle play. I'm going to replace the power steering pump and the gearbox soon. Maybe this weekend. It sucks not using AC just because I don't want that annoying sound at stop signs/lights. JEEP= Just Empty Every Pocket sums it up. I love my XJ, and soon enough, everything will be new.

 

NEW YORK CITY!!! That's where they make that dang nabit Pace picante sauce.

 

There should be a routing diagram on a sticker in the engine compartment.

 

I had a jeep that made that terriable noise u mentioned when the a/c was turned on. Its not your belt. I thought it was the blower motor , it wasnt. Compressor was bad.

 

So... Rather then replace the belt - which is a much more likely suspect - just replace the compressor?

 

Mine did the same thing. It turned out it was the auxilary electic fan with a dry bearing. Pulled it, lubed it and is still fine after 5 years.

This is an easy thing to check for. Unplug the fan, start vehicle, turn on AC, and check if noise is still there. If it is still squealing, shut down and plug fan back in. Look somewhere else. If the nois stops, replace or repair fan.

 

I learned from freegdr an awesome mechanic on here, to start with the small stuff first. U have to isolate the issue, otherwise u r fixing things that may not need repair. Time and money waster. Cranesrule: please give me more details on hoe to replace the belt. I am learning the mechanical terms as I go. Not sure what a tension puller is. Thanks.

 

if you read the thread you would have seen that she sprayed the belt with WD40 and the noise went away. that means the problem is the belt. not a bad compressor.

freegdr knows his stuff.