Blower Motor Resistor: Description and Operation
The blower motor resistor is mounted in the bulkhead on the passenger side of the vehicle under the cowl trim cover. It can be accessed for service by removing the cowl trim cover.The resistor has multiple resistor wires, each of which will change the resistance in the blower motor ground path to change the blower motor speed. The blower motor switch directs the ground path through the correct resistor wire to obtain the selected blower motor speed.
With the blower motor switch in the lowest speed position, the ground path for the motor is applied through all of the resistor wires. Each higher speed selected with the blower motor switch applies the blower motor ground path through fewer of the resistor wires, increasing the blower motor speed. When the blower motor switch is in the highest speed position, the blower motor resistor is bypassed and the blower motor receives a direct path to ground.
The blower motor resistor cannot be repaired and, if faulty or damaged, it must be replaced.