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.
In my personal experience the flat style plug is more reliable. Time to break out the test light. The thing is I have to go to the tail lights to make attachments.
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.