96 caravan ac gone please help im out of ideas

Help I am looking for help with my 1996 grand caravan. My ac stopped working with no warning. It has rear air that is also not working. I am not sure if things are related but for the past year the speedo, tach, and temp guage has worked intermittently. I started by replacing the control panel with a friends van and it worked fine in his van (the panel with the ac snowflake button) I then started looking at the compressor the compresor will not engage the clutch. I was able to engage the clutch by manually moving the switch in the relay and the clutch kicked on however there was no cool air comming out of the vents. I was able to check the r134 and it is at 45 psi with the compressor running on the low side. After having the compressor clutch running for a minute or two I reved up the engine and the compressor made a horrible noise, but doesnt make it each time I engage the clutch. I am not sure how to test the hi/low pressure switch or if there is a way to bypass it or test it to see if its bad. Any help would be appreciated.

There's times when safety dictates spending money. I would verify the high side pressure is good. You need to take it to the pros to do that. Short of that do you know someone with a full set of gauges and experience?

Unless you can find someone who has done it and knows, I wouldn't try bypassing the transducer. That envolves jumping the PCM and I've heard that thing can easily be fried. Not sure where it is but would your buddy let you swap his just to check it? He sounds like a brave and accomodating sole.

Is any of the tubing getting hot or cold with the compressor on? If so, and the pressures are good, then the compressor should be good.

:dunno: