bigspur76

I have a 2004 chevy suburban. Recently the AC would just automatically start blowing hot air out of both driver, passenger and rear vents. The fix was to turn off the ignition and crank up the suburban again. All vents would then blow cold air again. Then this past Friday, had an oil change and had the AC system checked for freon pressures, etc. The mechanic said he found no problems and AC worked well for him. I then drove the suburban home, 5 miles, and parked it overnight. The next day, cranked up the suburban to run an errand and the AC was not blowing cold air out of any vents. I noticed the air is not cold, not hot, but is warm. I have pulled the AC fuse under the hood and in the dash on the driver side to check them and then reinstalled the fuses again, cranked up the suburban, waited a couple of minutes and then turned on the AC. Same result, no cold air, but the air is not hot. I noticed that it does not sound like the compressor is cutting on. Suggestions?

kevinkpk

Well if you suspect the compressor not cutting on, you need to check to see if it is engaged or not.

bigspur76

how do I check to to see if it is engaged or not? I was going of off the sound the vehicle makes when the compressor turns on? Thanks!

kevinkpk

Watch it. If it is engaged look at the end, if it turns if not it isn't engaged.

bigspur76

I see the belt turning but don't see the clutch spinning.

kevinkpk

Well, something is not allowing the clutch to engage. Ok, it could be low freon, which I doubt, or low pressure cutoff switch. Can you see an electrical connector to the front (clutch) of the compressor? I don't know your mechanical level, but with the engine running, remove the connector, and reinsert it. It could be a loose connection. Go from there if no luck.

bigspur76

Thanks for the help. I am going to try to reinsert the connection in the morning. If that is not it, is there any way this could be an accutuator problem? It is odd that the air coming out of the vents is not hot like heat but it is also not cold. It is almost the same temp as outside air or maybe a little cooler. Maybe the mechanic that checked the pressures, etc left something loose or allowed some of the freon to escape and the level is just low. Hope to get to the bottom of this tomorrow.

kevinkpk

Yes. It also could be freon, whith an 04 I doubt. The thing is, you need to determine if the compressor is engaged all the time you have ac selected.