Circuit/System Description
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
The auxiliary blower motor control module is an interface between the HVAC control module and the auxiliary blower motor. The auxiliary blower motor speed control, battery positive and ground circuits enable the control module to operate. The HVAC control module provides a variable voltage to the auxiliary blower motor control module to request the selected auxiliary blower speed. The auxiliary blower motor control module provides a pulse width modulation (PWM) signal to the auxiliary blower motor in order to control the blower motor speed. The module supplies 12 volts to the blower motor through the auxiliary blower motor B+ circuit.