Temperature Blend Door Actuators

The DATC system utilizes two temperature blend door actuators to control two separate temperature blend doors that independently vary the LH side and RH side temperature settings, as desired. The temperature blend door actuators:

• are located on the heater core and evaporator core housing.
• move the temperature blend door on command from the DATC module.
• contain a reversible electric motor and a potentiometer. The potentiometer wiper is connected to the actuator output shaft and moves with the output shaft to indicate the position of the temperature blend door.
• are supplied a 5 volt signal and ground to the potentiometers. The voltage available at the wiper indicates the position of each potentiometer. The expressed value of the actuator wiper voltage is sent to the DATC module and is matched with an expected wiper voltage value. The DATC module then drives the actuator motor in whichever direction is necessary to make the actuator wiper voltage agree with the expected DATC module wiper voltage value.