When the Light Sensor senses light it will brighten your HVAC read out lights , and vise versa, also your instrument cluster ligtts ... makes seeing your instrument lights not too bright at night & not too dim during the day ...
Also the sunlight will make the Automatic climatic control put out more cool AC air, knowing the the truck needs more cooling during direct sunlight shining into the truck ...
Cosmic Charlie's post in 2008 Silverado hvac Light sensor functions. was marked as the answer
