Blower Motor (Heater Fan)

It usually sits behind the glovebox or under the dashboard on the passenger side, often directly behind the cabin air filter. Fan speed is set either by a resistor pack with fixed steps or by an electronic power module that varies speed smoothly. Because the fan also feeds the windscreen vents, a dead blower makes demisting difficult and is a safety issue in cold or wet weather.

A DC motor spins a squirrel-cage wheel that draws air in from outside or from the cabin and pushes it through the heating and cooling cores.

Typical faults are a fan that only works on the highest setting, a whine or ticking from worn bearings or leaves in the fan, and a completely dead fan. Before replacing the motor, check the fuse, the connector, the resistor or power module and the cabin filter, which can restrict airflow when clogged.