Okay so today going over railroad tracks I must have jarred something loose. I go to put on brakes and that buld light is come on when I press on pedal. At my next stop I get out to see what is out. My center light in the back window is out. So I take cover off and inspect bulb. It looks fine but I replace with spare that i carry. It seems to work fine until coming home and same tracks it goes out again. After fooling it seems that I may have a short or may need to clen terminals or contacts? It seems that when some of the wires are moved the light will come on? then as soon as I let go it goes off again. Any idea??