When you say the unit is not getting power, what do they mean by that? Anyway, turn your A/C on, pop the hood and see if your compressor is turning on and off. If it'* not, disconnect the clutch electrical connector at the pulley and use a test light to see if you have voltage at the connector. If nothing, you may not have enough pressure in the system to turn it on. I think someone disconnected the connector on the high side and jumped it to make it think it had the pressure. (for testing purposes only). Someone might chime in.
1997 Pontiac Bonneville SEi-SCRAPYARD
2000 Chevrolet Blazer LT 4X4 4.3L
2002 Chevrolet *-10 LS Ext Cab 4X4 5.7 V8