Blower Motor: Description and Operation

Front Blower Motor

Description






The blower motor is mounted to the bottom of the HVAC housing, on the passenger side of the vehicle. The blower motor assembly is a squirrel type blower cage (2) connected to a 12 volt, direct current motor located within a plastic housing (4). The blower motor has an integral wire harness bracket (1), three mounting provisions (3) and a wire connector receptacle (5).

The blower motor can be accessed for service from underneath the instrument panel.

Operation

The front blower motor is used to control the velocity of air moving through the front HVAC housing by spinning the blower wheel within the housing at the selected or programed speed (depending on control application).

On models equipped with the manual temperature control HVAC system, the front blower motor will operate whenever the ignition switch is in RUN and the blower motor control is in any position except OFF. On models equipped with the automatic temperature control HVAC system, the front blower motor will operate whenever the ignition switch is in RUN and the HVAC control power is ON.

In the MTC system, the front blower motor speed is controlled by regulating the path to ground through the blower control switch and the blower motor resistor. In the ATC system, the front blower motor speed is controlled by an electronic blower motor power module, which uses a pulse width modulated input from the HVAC control and a feedback signal from the blower motor to regulate the blower motor ground path. On both systems, the blower motor receives battery current through the totally integrated power module whenever the ignition switch is in RUN.

The blower motor and blower wheel are factory balanced and cannot be adjusted or repaired and must be replaced as an assembly if inoperative or damaged.