Air Speed - Front Control

WARNING: This page is about a different car, the 2002 Oldsmobile Bravada, 2002 GMC Envoy XL, 2002 GMC Envoy, and 2002 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.

The blower control switch is integrated into the HVAC control module. The two rocker type switches provide the vehicle operator the ability to select several blower speeds. The HVAC control module uses a bar graph type display to indicate the selected blower speed. The HVAC control module provides a pulse width modulated (PWM) signal to the blower motor through the blower motor speed control circuit. The blower motor changes speed based on the received PWM signal from the HVAC control module. Power and ground are provided to the blower motor through the battery positive voltage and ground circuits. When the HVAC control module is operating in AUTO mode, the system automatically controls the blower speed. Power and ground are provided to the HVAC control module by the ignition 3 voltage and the ground circuits.