What is a blower motor and where is it located?

A blower motor, also commonly referred to as an air conditioner (A/C) blower motor, heater blower motor, or a heater fan motor, is a major component to your vehicle's heating, ventilation, and air conditioning (HVAC) system. It is controlled by the knobs or buttons on the climate control unit. When your heat or A/C is turned on, it is what forces the cold or warm air from your vehicle's A/C and / or heating system through the interior vents, circulating it throughout the cabin. If your heat or A/C is turned off, the blower motor is just hanging around doing nothing. Even if a vehicle is not equipped with an air conditioner system, it will still have a blower motor assembly in order to circulate the outside air inside of the cabin, in addition to the heat.

The blower motor assembly mounts to the HVAC case or housing, which is normally located behind the dash of the vehicle. Some vehicles—such as SUVs and passenger vans—may also have a separate blower motor assembly mounted in the rear of the vehicle. These are simple direct current electrical motors. Attached to the motor is a wheel (also referred to as a cage or fan), which is spun by the motor, circulating the air within the housing and forcing it through the vents. The air will either be hot or cold depending if it is sent through the A/C or heater duct. In those cases where a vehicle does not have an A/C system, the outside air that passes through the ducts and is forced out of the vents by the blower motor is of the same temperature as it is outside of the vehicle, though it typically feels a bit cooler thanks to the velocity that it is forced out at.

How do I know my blower motor needs to be replaced?

As with all electrical motors, automotive blower motors can and will eventually fail. Over time and general use, the brushes inside the motor will wear, resulting in a reduction of power the motor can produce. Bearings are another common point of failure since these can lose lubrication and begin to dry, friction increases which may eventually cause the motor to seize. Early symptoms of this will be noise, such as a squeak or squeal, coming from the motor while operating. In addition, sometimes the wheel can be damaged causing poor or no output whatsoever from your blower motor. When diagnosing an inoperative blower motor be sure not to overlook other components such as the fuse, blower motor resistor, or a possible ground issue. If you are experiencing intermittent stopping during use, squealing noise from bearings, poor air circulation from your car's vents due to weak fan rotation, or simply no output at all, it is likely that you need to replace your HVAC blower motor.

Can I replace the blower motor myself?

Replacing the blower motor is not a complicated job. Most of the time it is as simple as finding the motor underneath the glove compartment or removing the glove compartment box to access it. The blower motor can usually be removed by loosening the screws or bolts on it and by disconnecting the motor harness. To reinstall, simply insert the blower motor in place, reconnect the motor wiring harness, and push the glove box in place if needed.