Single Zone Temperature Blend Door Position

WARNING: This page is about a different car, the 2014 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.

The single zone temperature blend door actuator moves the temperature blend door on command from the HVAC module.

The single zone temperature blend door actuator contains a reversible electric motor and a potentiometer. The potentiometer circuit consists of a 5-volt reference signal connected to one end of a variable resistor, and a signal ground connected to the other. A signal circuit is connected to a contact wiper, which is driven along the variable resistor by the actuator shaft. The signal to the HVAC module from the contact wiper indicates the position of the temperature blend door. The HVAC module powers the actuator motor to move the temperature blend door to the desired position. The desired temperature blend door positions are calculated by the HVAC module based on the set temperature, in-vehicle temperature and humidity, and ambient air temperature.

On the single zone system, the temperature blend door actuator is located on the top of the heater core and evaporator core housing.