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I have a 96 civic ex. I have AC issues that when driving it will go warm for a bit then cold (not at a stop). I can hear the compressor working. I had the system charged last year thinking that it wass low on freon, but the problem still presisted. I spoke with a mechanic and he said if the compressor or clutch was bad it would be making alot of noise. I was thinking it can be a bad pressure switch? any ideas?