Pacifica V6-3.8L VIN L (2005)
Control Module HVAC: Description and Operation
Rear
Blower Motor Power Module
A rear blower motor power module is used on this model when it is equipped with the automatic temperature control (ATC) heating-A/C system. The
blower motor power module is installed in the rear blower motor housing, which is located within the center floor console. The power module consists of
a molded plastic mounting plate with two integral wire harness connector receptacles. Concealed behind the mounting plate within the blower motor
housing is the power module electronic circuitry and a large finned, heat sink. The module mounting plate is secured with two screws to the rear blower
motor housing and is accessed for service by removing the front center floor console.
The rear blower motor power module is connected to the vehicle electrical system through a dedicated wire harness lead and connector of the body wire
harness. A second connector receptacle receives the wire harness connector from the rear blower motor. The rear 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 rear blower motor feedback voltage. The resulting
output drives the power module circuitry, which adjusts the voltage output received from the rear blower motor relay to change or maintain the desired
rear blower motor speed.
The rear blower motor power module is diagnosed using a DRBIII(R) scan tool.
The rear blower motor power module cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.