Ambient Temperature Sensor / Switch HVAC: Description and Operation

Ambient Temperature Sensor:

The ambient temperature sensor is a variable resistor that is mounted to the right side of the radiator yoke, behind the radiator grille. The ambient temperature sensor is connected to the A/Cheater control through a two-wire harness lead and connector of the vehicle electrical system. The A/Cheater control sends out a J1850 message to the overhead console.

The ambient temperature sensor cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.

The ambient temperature sensor is a variable resistor that operates on a five-volt reference signal sent to it by theA/C-heater control. The resistance in the sensor changes as temperature changes, changing the temperature sensor signal circuit voltage to theA/C-heater control. Based upon the resistance in the sensor, the A/C-heater control senses a specific voltage on the temperature sensor signal circuit, which it is programmed to correspond to a specific temperature.