05 blazer, when i turn on my ac it usually works and blows cold for a few moments and then a ‘cheep’ like sound comes out of the compressor area and the cold air stops and it blows warm, if i rev to about 3k rpm’s the cheep happens again and the ac starts blowing cold for a few more minutes. i’ve read a few threads but can’t seem to find anything like this happening. any advice is appreciated

 

Probably low on refrigerant. Best way is to connect gauges to it and see what your numbers are. You can get loaner gauges from AutoZoo. Search the interwebs for information.

 

I didn't know that, good info! Usuallu I just add a can, I might try the AZ gauges next time.

 

​​​​Yep, sounds like low refrigerant. After it drops below a certain psi, it'll start working intermittently, until it loses a bit more and stop altogether.

Common leak points for these are the shrader valves on the low side, high side, and behind the cycling switch on the dryer. The o-rings flatten over time and fail.

Good luck!

 

Best add a can while you can. If you wait till there's no coolant left, the compressor won't kick in and it's a lot more trouble.