Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Module, Power, Blower Motor: Operation
The rear blower motor power module is connected to the electrical system through a dedicated wire lead and connector of the rear Heating, Ventilation and Air Conditioning (HVAC) wire harness. A second lead and connector of the rear HVAC wire harness is connected to the rear blower motor.
The rear blower motor power module allows the microprocessor-based HVAC module to calculate and provide infinitely variable blower motor speeds based upon either manual blower switch input or the Automatic Temperature Control (ATC) programming.
The system uses a Pulse Width Modulated (PWM) circuit strategy. 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 provides a linear output voltage to change or maintain the desired rear blower speed.
The rear blower motor power module is diagnosed using a scan tool. Refer to DIAGNOSTIC CODE INDEX .
The rear blower motor power module cannot be adjusted or repaired and must be replaced if inoperative or damaged.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.