Temperature Blend Door Actuators
WARNING: This page is about a different car, the 2005 Mercury Mountaineer and 2005 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
The dual-zone EATC system utilizes 2 temperature blend door actuators to control 2 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.
- moves the temperature blend door on command from the dual-zone EATC module.
- contains 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.
- apply a 5-volt signal to one end of the potentiometers and ground to the other. The voltage available at the wiper indicates the position of each potentiometer. The expressed value of the actuator wiper voltage is sent to the dual-zone EATC module and is matched with an expected wiper voltage value. The dual-zone EATC module then drives the actuator motor in whichever direction is necessary to make the actuator wiper voltage agree with the expected dual-zone EATC module wiper voltage value.