Blower Motor Power Module

Power Module:

A blower power module is used on this model.The blower power module is installed in a mounting hole in the evaporator housing, directly behind the glove box opening of the instrument panel. The module consists of a molded plastic mounting plate with two integral connector receptacles. Concealed behind the mounting plate within the evaporator housing is the power module electronic circuitry and a large finned, heat sink. The module mounting plate is secured with two screws to the evaporator housing and is accessed for service by rolling down the glove box from the instrument panel.

The power module heat sink will get hot when in use. Do not touch the heat sink if the blower motor has been running. The blower power module cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.

The blower power module is connected to the vehicle electrical system through a dedicated lead and connector from the instrument panel wire harness. A second connector receptacle receives a wire lead connector from the blower motor. The blower power module allows the microprocessor-based Automatic Temperature Control (ATC) heater-A/C control module to calculate and provide infinitely variable blower motor speeds based upon ATC programming which uses a Pulse Width Modulated (PWM) circuit strategy. The PWM voltage is applied to a comparator circuit which compares the PWM signal voltage to the blower motor feedback voltage. The resulting output drives the power module circuitry, which adjusts the voltage output received from the blower motor relay to change or maintain the desired blower speed. The blower power module is diagnosed using a DRBIII(R) scan tool. Refer to Body Diagnostic Procedures.