Heater fan only works on low or cold but not high. It is a 1986 Pontiac 6000 SE.
Heater fan only works on low
This is a classic description of a failed blower motor resistor. Replacing the blower motor resistor will solve the problem.
Labor time to replace the blower motor resistor is 0.3 hours. So it doesn’t take long at all to fix it yourself. So look at the top of the firewall on the passenger side. You’ll see the electrical connector there. Unplug the connector and remove the two screws. Pull upward on the resistor and replace in reverse order.
Blower motor resistor replacement
- Disconnect the negative battery cable.
- Unplug the electrical connector at the resistor.
- Remove the resistor attaching screws(2).
- Remove the resistor from the evaporator case.