I was washing my truck and when I got done I cleaned the interior glass.While doing this I knocked the little round ball,if I am not mistaken it tells the computer whether it is day or night.Runs the light. I tried to fish it out and could not.Had it but backwards. Could never get it to come up face forward up. I guess the only thing is too either take the dash out to get to it if not too complicated or go to the dealership.