Temperature Sensor Input
Ambient Air Temperature SensorThe ambient temperature sensor is a temperature-sensitive resistor whose resistance varies inversely with temperature. As outside air temperature increases. resistance decreases. As outside air temperature decreases, resistance increases.
The heater and A/C programmer monitors the outside temperature signal and uses this information to display outside temperature on the heater and A/C control VF display and helps determine command signals.
Inside Air Temperature Sensor
Inside Air Temperature Sensor:
The inside air temperature sensor is a temperature-sensitive resistor like the ambient air temperature sensor. As outside air temperature increases, resistance decreases. As outside air temperature decreases, resistance increases.
A hose connected to the inside air temperature sensor continually draws passenger compartment air over the sensor, increasing the accuracy of the temperature reading.
The heater and A/C programmer monitors the inside temperature signal and uses this information to help determine command signals.
Sun Load Sensor
Solar Sensor:
The sun load sensor is a light-sensitive photo-diode that monitors the heat load of the sun on the vehicle. The sensors are located on top of the Instrument panel, on either side of the defroster grill, where sunlight can reach the sensors.
As sunlight intensity increases, resistance of the sensor decreases. As sunlight intensity decreases, resistance increases.
The heater and A/C programmer compares the sun load sensor reading to the inside temperature reading and then determines how much cooling is required to reach and maintain the desired SET temperature.