Town Car V8-4.6L SOHC VIN W (1999)
Air Door Actuator / Motor: Description and Operation
Blend Door Motor
The A/C electronic blend door actuator is located on the top of the plenum housing.
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Its function is to move the air temperature blend door on command from the control assembly.
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The A/C electronic blend door actuator 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 air temperature blend door.
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A 5 volt signal is applied to the ends 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 electronic automatic temperature control module and is matched with the wiper voltage
of the module potentiometer. The control module then drives the actuator motor in whichever direction is necessary to make the actuator wiper
voltage agree with the control module wiper voltage.
