Solar Sensor: Description and Operation

The sun load sensor is a light-sensitive photo-diode. The sun load sensor monitors the heat load of the sun on the vehicle. The sensors (2) are located on top of the instrument panel, on either side of the defroster grill where sunlight may reach the sensors.

As the sunlight intensity increases, the resistance of the sensor decreases. As the sunlight intensity decreases, the resistance increases.

The heater and A/C programmer performs the following functions:
1. Compares the sun load sensor reading to the inside temperature reading.
2. Determines how much cooling is required in order to reach and maintain the desired SET temperature.