2006 Chevy Express 3500 12 passenger van: HVAC auxiliary rear fan only operates in high from both controls. Is this caused by a defective resistor module? Where is the auxiliary fan resistor assembly in the vehicle?
I have found a couple of vendors that advertise an ACDELCO Part # 158623 as a Rear Blower Motor Resistor. Is this the correct part number.
Is there a wire harness between the switch assembly and the resistor? If so, any recommend part numbers for repair if wires were overheated?