Air Speed - Front Control

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2007 GMC Yukon XL, 2007 GMC Yukon, 2007 Chevrolet Tahoe, 2007 Chevrolet Suburban, and 2007 Chevrolet Avalanche. 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 2 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 blower motor control processor supplies a 5-volt reference to the HVAC control module on the blower motor speed control circuit. The HVAC control module pulls the 5-volt reference low towards ground to provide a blower motor speed signal. As the voltage decreases the blower speed increases. Power and ground are provided to the blower motor control processor 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.