Ambient Temperature Sensor / Switch HVAC: Description and Operation
Outside Temperature SensorTemperature Sensor Locations:
PURPOSE
The outside (ambient) temperature sensor, which is located on the top of the evaporator housing, sends outside temperature information to the push-button control unit for calculation of blend air flap position and other outputs.
CONSTRUCTION
The outside temperature sensor is a negative temperature coefficient (NTC) type resistor. As the surrounding temperature increases the resistance decreases.
OPERATION
The outside air produces a resistance value in the sensor circuit. The resulting current flow in the sensor circuit is recognized by the TCC control unit as a measurement of the outside air temperature.