When you look at all the schematics on ETRAILER.COM on wiring up trailer safety lights the BLACK WIRE seems to be HOT +12VDC... The WHITE WIRE coming from the trailer side of the 4-pin connector goes to frame ground up near where the connector wiring is at (Tongue of trailer)...
It also shows the
Brown-Tail/Running Lights
Green-Right Turn/Brake - Remember green has an R in it
Yellow-Left Turn/Brake - Remember yellow has an L in it
It looks like the fixture gets its ground from the metal outside fixture being screwed down on the metal frame...
Check out some of the wiring drawings on ETRAILER.com to see if any of that makes any sense for you particular application.
Paperwork with the new fixture should also identify where your wires are suppose to go as well...
Roy Ken
