Theory Of Operation
WARNING: This page is about a different car, the 2013 RAM 3500 HD and 2013 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.
The Evaporator Temperature Sensor is a variable resistor that changes in conjunction with temperature, or otherwise known as a thermistor. The Evaporator Temperature Sensor is located in the HVAC housing downstream of the A/C evaporator. The A/C Heater Module monitors the evaporator temperature by monitoring the voltage change of the Evaporator Temperature Sensor Signal circuit. If the monitored voltage drops below or rises above a predetermined voltage, a Diagnostic Trouble Code (DTC) will set. For further information, refer to SENSOR, EVAPORATOR TEMPERATURE, OPERATION .