The automatic lights will turn the headlights (as opposed to the DRLs) on when the ambient light levels drop to the appropriate level - but unless the vehicle was supplied with automatic headlights there is no ambient lights sensor installed.
There at three different models of the ambient sensor available; One senses temperature, another senses light levels and the third senses both. As you might imagine, the temperature sensor is used with the automatic air conditioning. If you have neither auto air or auto headlights then thee is no sensor - it shows up as a small dome poking out of a hole in the center of the dash.
DRLs are quite another matter; A DRL switches on the headlights at half brightness (some Journeys use the parking lights) when the headlights are switched off and the vehicle's engine is running and not in Park.
Both features require sales codes to function.
It may be that if the switch is in 'auto' and vehicle doesn't detect the sensor it will presume it is night as a failsafe, in which case your headlights and tail lights would always be on wen the engine is running.
