AC went out so it was replaced for $2400. After a couple days it started letting off a high pitched whistle. Not consistent, but often… the AC starts losing its coolness for several minutes. After a couple minutes, it’s fine.

Had a bad jump start that fried a few things a few months ago. Replaced battery and alternator, so those are both new, and replaced the 100 amp mega fuse and A/C relays. The truck started and ran for several weeks, but then one day turned the key and it did absolutely nothing...also, absolutely NO lights on the dash display except for the check engine light. Had a friend test with scanner and it can't link with computer. Got a new programmed PCM, installed it, and same problem. I think it's a relay, but no idea which one.
Also, we've noticed that now the brand new battery goes dead quickly, like, in about 3 weeks. I just think that's awfully quick for a new battery to go totally dead. It's as if something is stuck ON and draining it. Any help would be greatly appreciated!

All off a sudden ac stopped working an blowing hot air the Freon is full plenty of pressure but compressor won't kick on I checked the pressure valve sensor on the line jumped the plug with a wire an compressor still doesn't work