Air Speed - Auxiliary - VIN 3: Notes
WARNING: This page is about a different car, the 2003 Oldsmobile Bravada, 2003 GMC Envoy XL, 2003 GMC Envoy, and 2003 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
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.