Temperature Control Switch
Temperature control switch is part of a temperature control module, attached to control frame with 2 screws. The module contains a printed circuit board and a linear potentiometer. The potentiometer switch is mechanically coupled to potentiometer wiper.
The temperature 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 position of temperature blend door.
Battery voltage is applied to ends of each potentiometer. The voltage available at each wiper indicates position of the potentiometer. The actuator wiper voltage is sent to the control module and matched with the wiper voltage of the module potentiometer. The printed circuit board then drives the actuator motor in whichever direction is necessary to make the actuator wiper voltage agree with the control wiper voltage.