Blower Motor Resistors
The blower motor resistor is a part of the fan that blows into the cabin of the car and controls the speed of the A/C or heater. The resistor controls the speed of the fan when A/C or the heater is in use. There are two general types of resistor, a mechanical device and a circuit board type. The mechanical resistor has coiled wires that have different resistances and each wire represents a different speed on the blower. The circuit type has a circuit board with a fully integrated circuit for electronic control of the blower. The unit is quite small, not more than about 2x3. It is located very near the blower itself. In order to repair the unit, the blower must be located. Once that is done the resistor is usually attached to the blower with small screws. Testing the resistor before replacing it is advisable to ensure that the proper repairs are made.