The first thing I did was have the refrigerant top off. I was as happy as a pig in Hollywood until I went on a long drive. The a/c went from nice and cold to warm and muggy. Looking for an answer I started to check out the sensors. I ruled out the both the pressure sensor and the fan sensor showed in the pic. The problem is the voltage to the low pressure sensor. It must have something to do with the climate control unit. What where and how? What can be done beside replacement? Where is the climate control unit?How can I check it?