Trailer Wiring 4 Pin To 7 Flat Diagram. Not sure which wires attach to what on your trailer connectors? Cut the four-pin plug off of the trailer harness.
The following trailer wiring diagram(s) and explanations are a cross between an electrical schematic and wiring on a trailer. Does one of your turn signals not work and you're not sure Various styles of connectors are available with four to seven pins to allow transfer of power for the lighting as well as auxiliary functions such as electric. The three additional pins are: trailer brakes, back-up lights and trailer battery charging.
Not sure which wires attach to what on your trailer connectors?
Referring to a wiring diagram for a trailer comes in handy during installation.
But wiring a trailer may not be easy. The first step in wiring your trailer cables is to ground the white cable first. These plugs are typically flat, with the pins set in a row. "Trailer Wiring for the Do-It-Yourselfer." trailerwiring.com.