Auxiliary Air Speed

WARNING: This page is about a different car, the 2006 Pontiac Montana SV6, 2006 Chevrolet Uplander, and 2006 Buick Terraza. However, it is still accessible from the selected car via links, so may be relevant.

The auxiliary blower motor is controlled by the front auxiliary blower motor switch. If the vehicle is equipped with rear DVD (U32), the auxiliary blower motor can be controlled by the overhead console, vehicle entertainment system (VES). The front auxiliary blower switch must be in the AUX position in order to control blower speed from the VES. The VES will send a class 2 message to the HVAC control module requesting a blower motor speed.

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, auxiliary blower motor speed signal, blower motor speed control and ground circuits enable the control processor to operate. The HVAC control module sends the commanded blower motor speed to the control processor through a 0 to 6-volt linear ramped blower motor speed control circuit. As the blower motor speed control voltage increases, the blower motor speed increases. The control processor sends the actual blower speed to the HVAC control module through a 0 to 12-volt blower motor speed signal circuit. The control processor uses the blower motor ground as a low side control to adjust the blower motor speed. The underhood fuse block supplies 12 volts to the blower motor through the blower motor voltage supply circuit.