A heater blower motor operates the fan that circulates cold or hot air into the passenger compartment of a vehicle. The heater blower motor can be located beneath the hood of a vehicle or under the dashboard near the circuit breakers.
Symptoms of an old or defective heater motor blower include little or no airflow from the air conditioning vents and abnormal noises or vibrations during the operation of the air condition or heater system.
The heater blower motor is controlled by a series of buttons and switches on the dashboard of the vehicle. These buttons control the speed of the heater blower motor through a series of resistors. The resistors are housed in a resister module that is located beneath either the dashboard or the hood of a vehicle. When the resistor module for the heater blower motor malfunctions or burns out, the motor is only able to operate at one speed setting. The resistor module should be replaced to restore multiple speed settings to the heater blower motor. Usually, the module can be purchased at most local auto repair stores for less than $25. The installation process for a new resistor module is relatively straightforward. Simply locate the old resistor module, remove the screws that hold it in place, change out the old resistor with the old one and reconnect any electrical connectors.