Please help! I have a 1982 mustang Gt with factory air. When the a/c is engaged, the compressor won't kick on. If I use a jumper wire from the battrey to the compressor it kicks on and blows super cold air. I have a new low pressure switch. When I tried to jump the terminal on the low pressure switch it should kick on the compressor,but has no power. I checked the inside switch......when put in the a/c position it does energize the a/c idle solenoid. Refrigerant is not low. I do have some wires not connected to anything.