Air Temperature Actuator
WARNING: This page is about a different car, the 2003 Pontiac Aztek and 2003 Buick Rendezvous. However, it is still accessible from the selected car via links, so may be relevant.
The air temperature actuator is a 3 wire bi-directional electric motor. Ignition 3 voltage, ground and control circuits enable the actuator to operate. The control circuit uses a 0-12 volt linear-ramped signal to command the actuator movement. The 0 and 12 volt control values represent the opposite limits of the actuator range of motion. The values in between 0 and 12 volts correspond to the positions between the limits.
When the HVAC control module sets a commanded, or targeted, value, the control signal sets to a value between 0-12 volts. Actuator shaft rotation is the results of a commanded position input by the vehicle operator. With a new actuator commanded value action, the maintained actuator control value is changed.