I bought this car from a person who said the AC and heat never worked. I changed the heater core to get that out of the way, they said it was always bad. While I had the blower out I tested it to make sure it works. I went to work on the AC and found that the adjuster low to high does not work. I changed the Resistor, and checked the Fuse in the box and all were good. I did replace the control assembly and still nothing. I checked the harness with the four wires that plug into the back of the control and it does not have power. What am I missing, is there a relay, where do those wires lead and connect to could they not be plugged in. HELP PLEASE!!!