Phillfam99
10-16-2006, 12:10 PM
Hey, I just bought a 66 C10 Step side. I had to replace the underdash wiring harness in it. I also put in a complete heater system (From control knobs to the core). On back of the control knobs there are four wires coming out. Blue, Orange, Yellow, and brown. I have connected the brown wire to the fuse box heater connection. The other three wires, I have no Idea where they are saposed to go. The underdash wiring harness that I have has no more connections available. If anyone has any idea what the other three wires are for, please reply.