Not sure where to begin. Just replaced a/c system last month. Compressor, condensor, evap, and hard line with orfice tube. Everything worked great till the other day when italian started blowing hot air. The clutch would not engage. Checked the fuses. All are good. So then I unhooked the power plug for the compressor to check power. Yes it has power. But once I plug it back into the cimpressor all power is gone. I can jump the compressor and make it engage but what could make it loose power when plugged into the factory harness? Tipm issue, pressure loss, or something else? Thanks

 

Freon leaked out most likely so low pressure switch keeps compressor from kicking on. You should be able to run a jumper wire across the wires for the lp switch and the compressor will start, the switch protects the compressor from damage from running low on freon because it contains the oil that lubes the compressor. You probably have a small leak like an oring or somthing.