Sun Load Sensor
WARNING: This page is about a different car, the 1999 Cadillac Eldorado and 1999 Cadillac DeVille. However, it is still accessible from the selected car via links, so may be relevant.
The sun load sensor is located under center defroster grille, at base of windshield. This sensor uses a light sensitive photocell to measure amount of sunlight hitting vehicle. Sensor voltage is lowest in direct sunlight; highest when shaded. ACM processes this signal together with temperature signals to determine the cooling necessary for maintaining selected interior temperature.