1..2..3.. Go! I get 12v to the socket but with bulb in the socket I get 0. 1No light, 2 it's not the bulb, 3. the bulb cannot short to ground 4. It's single filament, the other high bulb works fine, 12v wether bulb is in socket or not. 5 it is not relay. 6 it is not the high/low switch. What's this mean?