A/C Help

Installed a new A/C compressor, dryer, and expansion value. Took it down to the local Tuffy shop to have them evacuate and fill. Everything well great. As I was driving the new morning, the A/C stop working. I got out to look and the a/c clutch was no longer engage. I check the charge on the a/c low side and it has about 40-50 psi. I looked through all the fuses and started pushing on all the cable connections to the a/c. When I started pressing and pulling on the connctor to the hi-low pressure switch, the clutch engaged. I left the car sitting in park for about 15 minutes and a/c was still running. I then took it out for a drive and before I could make 200 yards from the house, it stopped again. I went back through and could not get it going again. I jumped the a/c clutch to the battery and it will engage so I don't think it is the clutch. I am not getting any power to the cable that power the a/c clutch. I also pulled the connector off the hi-low pressure switch and jumped a wire across the two leads (suggested by Tuffy) and it still did not work. Does that mean the pressure switch is OK?

Any ideas?

Thanks in advance.

Honda Civic DX (1.5 L)
1995