I've noticed that my dash air (converted to duracool) is not blowing cool air.

First thought was to top off the refrigerant. I connected my gauge set, turned on the engine and AC and noticed the compressor was not on. I jumped the two leads on the pressure switch and got the compressor to come on. I started to add duracool, but noticed that the low side pressure was 60 and the high side was less than 50 with the compressor turning. I think low side should be about 20-25 and high side on a hot day should be something like 150 - 200 psi range. I'm thinking that I have a bad compressor. It's probably the original. I replaced the clutch 4-5 years ago. Or maybe the expansion valve is clogged. In the event I have to change out the compressor and receiver dryer I do have a vacuum pump and a large supply of refrigerant.

Any ideas on how to confirm a bad compressor?

rjw wrote on Mon, 30 June 2014 15:30

I've noticed that my dash air (converted to duracool) is not blowing cool air.

First thought was to top off the refrigerant. I connected my gauge set, turned on the engine and AC and noticed the compressor was not on. I jumped the two leads on the pressure switch and got the compressor to come on. I started to add duracool, but noticed that the low side pressure was 60 and the high side was less than 50 with the compressor turning. I think low side should be about 20-25 and high side on a hot day should be something like 150 - 200 psi range. I'm thinking that I have a bad compressor. It's probably the original. I replaced the clutch 4-5 years ago. Or maybe the expansion valve is clogged. In the event I have to change out the compressor and receiver dryer I do have a vacuum pump and a large supply of refrigerant.

Any ideas on how to confirm a bad compressor?

You just diagnosed it as a bad compressor. Did you observe that the compressor shaft is actually rotating ? If the clutch were bad it may not rotate if it is in fact rotating I would say the compressor has bad valves or broken internal parts. Your gage may be a little out of calibration as it isn't possible for the high side to be lower then the low side. Last month I started charging a friends 1970 el camino after the a/c had not run for several years the high side was around 20 lbs higher then the low . I told him the compressor wasn't pumping and we would probably have to replace it. I figured what do we have to lose so I dumped in some R22 on top of the can of Duracool . I had him put a few miles on it and I'll be damned it started pumping so I evacuated it and put in a couple of cans of Duracool . Sometimes you get lucky.

Whats the idea behind the R22? Or did you mean R12?