Blower Motor Resistor: Description and Operation

The heater blower motor switch resistor has the following features:
- The assembly is located in the passenger compartment on the evaporator housing next to the blower motor assembly.
- Three resistor elements are mounted on the resistor board to provide four blower motor speeds.
- Depending on the heater blower motor switch position, series resistance is added or bypassed in the A/C blower motor circuit to decrease or increase A/C blower motor speed.
- An overheating device (thermal limiter) will open the resistor coil when the temperature reaches 121°C (250°F) interrupting the blower motor operation in all speeds except high.
- The thermal limiter cannot be reset and is not serviceable