Squealing I have a 1993 Mazda 626 2.0 liter. Cannot get the AC belt to stop squealing/ ticking noise. The A/C compressor has been replaced, and the A/C belt is as tight as you can get it. The belt squeals when you put fan on.

The belt has most likely moved either in or out on the bottom pulley. Check it first. I had the same problem it looked ok but was out one groove missleading designed pulley.

Try to tighten the belts a little firm.Sounds like when engine idling no squelling only when about to take off .Some times belts may seem ok on the outside but if you look on inner side you tend to see cracks in the belts .

Odd,possibly the AC is overcharged,or a pulley(either tensioner or
PS ) is out of line. Wish I knew what kind of vehicle. Might help.

So many mechanics, so little consensus. Sounds pretty common.
I can't say as to why hot and cold only when moving, but it sounds like a weak performing system.
As for the squealing, I would suggest removing one belt at a time, and see if one eliminates the squeal. That would be the problem belt or pulley or component. Also, if you have any idler pulleys (a stand-alone pulley) on the belt system, be sure and check them as well. Spin them without the belt on, and see if they make any noise.
It would seem you need a mechanic who is willing to spend some time with you on this to find the problem. When you find a good one, you will know it by his output, and make yourself a regular customer. Good luck.

For squealing noise problem,click the link below :----http://technoanswers.blogspot.com/2012/01/squealing-at-start-up-on-car.html
--------This will help.Thanks.

it may not be the belt that is the problem it could be the A/C clutch that is squealing or the A/C compressor unit cheers.

The squealing is from the crankshaft p[ulley turn the belt on another pulley that is not turning as faster, Let it sqeal long enough and it will burn the belt in half. The pulley on the A/C maybe turning freely, but when you engage the A/C, the compressor itself is not, causing it to squeal. My guess is that the compressor is locking up or you have added to much freon. Having to much freon causes to much pressure buid up and will stop the compressor.

idler pulley or belt tensioner usually makes the squealing noise..put a long steel bar (extension) near the pulley and listen to the noise by putting your ear near the tool and you will hear it

check all pulleys. and also, check the air conditioner compressor. it may need to be serviced. the compressor can make a squealing noise at times if the bearings are bad. make sure the tension is correct as well.