Temperature Blend Door Actuators
WARNING: This page is about a different car, the 2005 Mercury Montego, 2005 Ford Freestyle, and 2005 Ford Five Hundred. However, it is still accessible from the selected car via links, so may be relevant.
The temperature blend door actuators:
- are located on the heater core and evaporator core housing.
- move the temperature blend doors on command from the dual-zone EATC module.
- each 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 doors.
- applies a 5-volt signal to one end of the potentiometer and ground to the other. The voltage available at the wiper indicates the position of the 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.