Temperature Blend Door Actuator

The EATC system utilizes a temperature blend door actuator to control the temperature blend door. The temperature blend door actuator:

• is located on the plenum chamber.
• moves the temperature blend door on command from the 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.
• receives a reference voltage to one end of the potentiometer. The voltage available at the wiper indicates the position of the potentiometer. The expressed value of the actuator wiper voltage is sent to the EATC module and is matched with an expected wiper voltage value. The EATC module then drives the actuator motor in whichever direction is necessary to make the actuator wiper voltage match the expected EATC module wiper voltage value.