Ambient Temperature Sensor / Switch HVAC: Description and Operation

Two temperature sensors are incorporated into this system to help maintain desired temperature levels automatically. The in-vehicle sensor is located on the instrument panel carrier, and the ambient or outside sensor is located under the air inlet screen in the engine compartment. Both of these sensors contain thermistors or temperature sensitive resistors. These provide the basic control inputs for the systems automatic function. The temperature sensors work in this way: if 70 degrees F setting is selected and ``Auto'' setting is selected, the difference between the two sensor signals is determined by the control panel which will in turn change the temperature door and mode actuator as required. The in-vehicle sensor will signal the controller when the vehicle is reaching or has reached the desired setting and the controller will in turn send out the signal to adjust accordingly.