2007 Silverado. Dome lights don't come on when door is opened. Dome light dash push button switch (to the right of headlight switch) is in the extended position. Dome lights will turn on manually if the push button switch (a.k.a. dash light dimmer) is twisted to extreme clockwise position, but in that mode they simply remain on even when door is closed. Any suggestions on what I am up against with these symptoms?