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.
