AHA. After reading i figured out what you were talking about.
In our housings, you have the one wire that goes in, thats for power, Now yes there is a ground, but the ground is NOT a wire, its that metal peice, so only when the metal is touching when you have a bulb lodged in there to hold it in place, does it make the complete ground and can you turn on the bulb. Try taking out the bulb and not having that metal touching the metal base of the bulb, it doesnt complete the ground. The metal base of the h3 bulb conducts the ground from that lil metal clip in there and shit, so if that doesnt touch the bulb, no ground, no light. Get what im saying.
So the metal in there is the ground, and has to touch the bulb to complete the ground, so there is no wire. So what you have to do is cut that, run in as a real wire and there you go. You have your neg and positive. I just ripped all that out of the inside of my harness, ran in the wires from the ballast, filled it with water proof rubber gasket sealent shit, and plugged in the bulb, and there we go.