The heater blower motor is located behind the dashboard. The driver can control the speed at which the blower motor operates via buttons, slides, or dials on the dashboard. The blower motor forces air through a heater radiator behind the dashboard to provide heat for the passenger compartment. Alternatively, the motor blows air through the air conditioning evaporator to provide cold air to the passenger compartment.
Heater motors on many vehicles may operate only at high speeds if the heater control resistor unit fails. Mice may also build nests in the heater blower fan, filling it with nesting material that can cause the fan to jam or malfunction.
To access and replace the blower motor, some disassembly of the dashboard and interior trim is necessary.