Air Distribution - Auxiliary Control

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2003 GMC Yukon XL, 2003 GMC Yukon, 2003 Chevrolet Tahoe, 2003 Chevrolet Suburban, and 2003 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

The auxiliary HVAC system provides ventilation for the rear seat occupants. The rear seat occupants will exercise control of the auxiliary air delivery modes, air speed and air temperature setting.

When the auxiliary mode switch is toggled, a signal is sent to the auxiliary mode actuator through the auxiliary mode door control circuit. Power and ground are supplied to the auxiliary mode actuator through the ignition 3 voltage and ground circuits.

When the HVAC control module is ON, the air that is delivered to the auxiliary HVAC system is the low auxiliary blower speed. When the operator selects medium blower speed, power is delivered to the auxiliary blower motor through the auxiliary blower motor medium speed control circuit. When the operator selects high blower speed, power is delivered to the auxiliary blower motor through the auxiliary blower motor high speed control circuit. Ground is provided to the blower motor through the ground circuit. Power and ground are provided to the auxiliary HVAC control module through the ignition 3 voltage and ground circuits.