Hi,new guy here with an AC question.I have a 1996 Yukon that I have had for 2 years and the AC has never worked as long as I have had it.The previous owner said he had it checked and the compressor is bad.I unplugged the harness that connects to the compressor and checked for power.There are 2 wires going into the connector,green and black.I checked both wires with a test light and dont have power on either one.Could this be my problem?