Blower Motor Power Module: Operation

WARNING: This page is about a different car, the 2005 Dodge Grand Caravan, 2005 Dodge Caravan, and 2005 Chrysler Town & Country. However, it is still accessible from the selected car via links, so may be relevant.

The front blower motor power module is connected to the vehicle electrical system through a dedicated lead and connector of the front HVAC wire harness. A second connector receptacle receives the wire harness connector from the front blower motor. The front blower motor power module allows the microprocessor-based automatic temperature control (ATC) A/C-heater control to calculate and provide infinitely variable blower motor speeds based upon either manual blower switch input or the ATC programming using a pulse width modulated (PWM) circuit strategy.

The PWM voltage is applied to a comparator circuit which compares the PWM signal voltage to the front blower motor feedback voltage. The resulting output drives the power module circuitry, which provides a linear output voltage to change or maintain the desired blower speed.

The front blower motor power module is diagnosed using a DRBIII® scan tool. Refer to BODY DIAGNOSTIC PROCEDURES .

The front blower motor power module cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.