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Noise when I turn on a/c / easy way to test belt?

Hi, when i turn on the a/c, it makes an awful squealing noise for about 3 sec then goes away. I’m guessing its either a) belt, b) a/c clutch c) compressor or d) other. What’s an easy way to test if its the belt? Seems like I remember something about spraying (water, hairspray, oil, spraypaint, jetfuel, plutonium, something) on the offending belt to test it.



Here’s another clue: with the a/c on, it makes a very minor ‘chirp’ sound about once per minute. Only with a/c on.

Sounds like a glazed belt. Try the water test. Depending on the mileage it may be time to change any idler or tensioner pulleys too.

roger that and thanks. I can change a belt, and tighten the tensioner. Just wanted to try to figure how how to isolate the problem before taking it in.