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When the weather first starting getting warm last month, I turned on my A/C and it didn't work. The air coming out of the vents was warm and humid. A few days later it started working just fine and has worked fine ever since. I noticed that it has been hotter ever since it started working.

I have had this problem in previous years. Sometimes it will work fine and sometimes it will not. Does anyone have ideas of what could be wrong?

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Make, Model, Year? – Move More Comments Link To Top Apr 19 '11 at 1:52
@Larry 2003 Pontiac Bonneville. – Stainsor Apr 21 '11 at 12:33
up vote 4 down vote accepted

I would check the freon level, but it sounds like the compressor. In my truck when the A/C compressor started to go out that exact thing happened, the air would blow out warm and humid. The easiest thing to check first is to ensure that the A/C condenser fan is working. It is in front of the motor, it blows air across the smaller radiator that cools the compressor. When the compressor over heats it gives the exact symptoms you described with the warm humid air.

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Thanks. It has been fine ever since I posted the question. Do compressors fail slowly or all at once? – Stainsor May 16 '11 at 13:43
I have heard of alot giving symptoms of being low on freon, but the failure itself is usually pretty quick. – Zencyl May 16 '11 at 18:46

The fact that it didn't work and then did with no changes points to a problem in either the electrical or mechanical linkage and it is the type of problem that is the most difficult to figure out. As a rule compressors work or they don't and when the freon is too low they have a tendency to short cycle, which cools but not well.

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Thanks. I wish I could have accepted both answers. – Stainsor May 18 '11 at 16:14

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