I have a1992 Z and recently just fill it with freon. The compressor clutch did not kick on. It does come on when i use a jump wire in place of the relay. I'm thinking my low pressure switch on the dryer is bad. My question is "There are two set of plugs from the wire harness, one plug is brown which is a lower pressure switch, the other one is gray and the other end is screw to the frame. What is and does this plug for? The gray one that is.