Passenger rear dome wiring

[zack_008]

Hoping to get some help identifying wires. Because mines a camper I don't know what was an add on and what may be remnants of a regular van. Mine has a dome light just inside the slider with a connector with hot/ground (red/black). On the back side of the light there were two more wires, black/white. The black was half hazardly attached to a separate pin on the dome (still not sure the function of this second pin) and the white wire was just cut and hanging inside the c pillar. I don't know what the white wire goes to. I've ohmed out the black and confirmed it's a ground. The white wire reads like a hot wire when ohmed. And the pin on the back of the dome has impedance like it's not a ground. No clue what's going on. Anyone know what the white wire goes to? The length doesn't match up with anything unless it's a center mount dome ( which mine doesn't have cause of the poop top). I originally pulled it apart because it was only lighting one florescent light in "door" but switching to "on" did nothing.

Ones in red are the wires in question. And it runs towards the back of the van. Blue is the connector that actually fits the light.