Air Distribution - Front Control: Notes

WARNING: This page is about a different car, the 2002 Pontiac Montana, 2002 Oldsmobile Silhouette, and 2002 Chevrolet Venture. However, it is still accessible from the selected car via links, so may be relevant.

When the mode switch is turned, a signal is sent from the HVAC control module to the mode actuator through the mode door control circuit. When the logic receives the signal, the mode door moves into the desired position.

Power is provided to the mode actuator through the ignition 3 voltage circuit. Power and ground are provided to the HVAC control module by the ignition 3 voltage and ground circuits.

When a desired mode setting is selected, a variable resistor is used to determine the mode door position signals value. The resistor changes the 12-volt signal coming into the actuator and varies the voltage to move the actuator into proper position, based on the signal from the HVAC control module. Ground is provided to the mode actuator by the ground circuits. When the mode actuator sees an open in the control circuit, the actuator defaults to 6 volts and positions the mode door to the floor.