Air Distribution - Front Control: Notes

WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

When a mode switch position is selected, a signal is sent from the HVAC control module to the mode actuator through the mode door control circuit. The mode actuator moves the mode door to the desired position.

When the mode door moves to a desired position, a variable resistor within the actuator is used to create the mode door position signal. The HVAC module uses the mode door position signal to determine the actual mode door position. The left instrument panel fuse block provides power to the mode actuator through the ignition 3 voltage circuit and the IP wiring harness junction block. Power and ground are provided to the HVAC control module by the fuse block through the ignition 3 voltage circuit and the ground circuits through the right instrument panel junction block. A 5 volt reference signal is sent to the actuator through the 5 volt reference circuit, through the right instrument panel junction block, to the mode actuator.