My AC was working perfectly, I was driving up a steep hill and the AC was blowing out very cold air. All of a sudden it turned to very hot air. There was no gradual loss of cold air, it immediately went from cold to hot air.

I tried having freon added but it would not allow them to add freon. I was told that the compressor had frozen up and that I would need to have it replaced. I have had several estimates and they are all over $1,200.

I can't afford to have it replaced so I am driving in a sweat box during the summer months.

I bought the car used in January of 2011 with 50,000 miles. The problem with the car is that the heat does not get warm/hot when the car is idling. Basically I could let the car warm up for 20 minutes and heat would still be cool. The temperature gauge would be at normal level and there was no problem with the thermostat (this model uniquely has two thermostats both of which I had replaced).

What I would do is allow the car to only briefly warm up and then get immediately on the road. When the rpms are revving and/or the car is accelerating, the heat will get warm. But as soon as you come to a dead stop, it will go back to blowing out cool air.

On really cold days I would put the car in neutral to rev the engine while at a dead stop.

Eventually, and after driving for about 20 minutes, the heat will stay warm while being idled. Not quite as warm as while driving, but warm enough.

Was told the problem might be some sort of blockage with the heating vents that requires them to be manually moved to allow hot air in. Uncertain if that is the case but I am sure it has nothing to do with the thermostats. The mechanic who suggest that fix did spend extensive time trying to diagnose the problem and initially changed the thermostats.