Dakota Quad Cab 2WD V8-5.9L VIN Z LDC (2002)
Ambient Temperature Sensor / Switch HVAC: Description and Operation
AMBIENT TEMP SENSOR
Fig. 10 Ambient Temperature Sensor
The ambient air temperature sensor is hardwired to the HVAC control and the HVAC control sends out a J1850 message to the overhead console. The
ambient temperature sensor is a variable resistor mounted to a bracket that is secured with a screw to the right side of the radiator yoke, behind the
radiator grille and in front of the engine compartment.
For complete circuit diagrams refer to Wiring. 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 the HVAC control head unit. The
resistance in the sensor changes as temperature changes, changing the temperature sensor signal circuit voltage to the HVAC control head unit. Based
upon the resistance in the sensor, the HVAC control head unit senses a specific voltage on the temperature sensor signal circuit, which it is
programmed to correspond to a specific temperature.
