Heating and cooling fan not working?

LKEESLICK

MEMBER
2010 CHEVROLET HHR
160,000 MILES

The blower was only working on high, picked up used motor, relay, and resistor. Swapped out relay, not fixed. Swapped out resistor, not fixed. Unplugged the old motor without taking out of housing and plugged in different motor but it didn't spin like it did on my daughter's Ford. Do you think it is a bad motor I picked up or a bad control panel?

Saturday, July 8th, 2023 AT 2:15 PM

1 Reply

JACOBANDNICKOLAS

MECHANIC
110,176 POSTS

Hi,

If the fan is still working on high only and you are sure the resistor is good, then it is likely the switch itself. Power from the relay goes to the motor and then to the resister. The switch is what determines the speed by providing a ground to different resister pins which completes the circuit.

If the ground was faulty, it wouldn't work on high. However, keep in mind, in most cases, when they only work at high speed, it is a faulty blower motor resistor. If the one you used tried wasn't new, it could be bad as well.

Let me know.

Joe

I attached the wiring schematic below so that you have a reference.

Images (Click to make bigger)