RAM 1500 Truck 2WD V6-3.9L VIN X (1999)
Ambient Temperature Sensor / Switch HVAC: Description and Operation
DESCRIPTION
Ambient air temperature is monitored by the compass mini-trip computer module through the ambient temperature sensor. The ambient
temperature sensor is a variable resistor mounted to a bracket that is secured with a screw to the underside of the hood panel near the hood latch
striker in the engine compartment.
The ambient temperature sensor cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.
OPERATION
The ambient temperature sensor is a variable resistor that operates on a five volt reference signal sent to it by the compass mini-trip computer
module. The resistance in the sensor changes as temperature changes, changing the return circuit voltage to the compass mini-trip computer
module. Based upon the resistance in the sensor, the compass mini-trip computer module senses a specific voltage on the return circuit, which it is
programmed to correspond to a specific temperature.
