Trailer Wiring Diagram 7 Pin 5 Wires Flat. The following trailer wiring diagram(s) and explanations are a cross between an electrical schematic and wiring on a trailer. It's OK, within the standards, to leave out wires for your custom.
If you get the wrong one, there's a permanent current drain.
Wiring for the plugs is more or less standardized.
It's OK, within the standards, to leave out wires for your custom. I found a diagram on the web (see attached), but can't tell if the diagram is from the front or rear of the connector - ie if you unplugged it at looked at the side that mates with. The good news is that there are The not-so-good news is that the colors of the wires do not correspond with the standard wiring diagram.