One reason for trying to make certain it is the resistor is that I have NOT found a new resistor for this truck yet. Anywhere at any price. The resistor for a 1985 is readily available and cheap.


If I'm reading it correctly, the wiring diagram indicates the current flows from the fuse panel to the switch, then to the resistor and on to the motor. I'm NOT very confident that this diagram is correct. Some of the things I see on the truck do NOT match the wiring diagram. Perhaps the wiring diagram is for trucks without air conditioning. Apparently there were some significant differences in the HVAC systems of air conditioned and non air conditioned trucks.