Standard 4-Pole Wiring Harness - For use with vehicles that have adequate power and standard wiring system, these simply connect into existing wires on the vehicle and have a 4-pole flat connector to attach a trailer. Converter - For use with vehicles that have separate turn and brake light wires. Some vehicles send only one signal per wire.. Here are two wiring diagrams for the 7 pin 'N' type trailer electrical plug. The first diagram is a simple set up of two brake lights, two indicators and two side lights. Click on the image below to enlarge it. The second diagram shows two brake lights, two indicators, two side lights and a fog light. Click on the image below to enlarge it.
7 Pin Trailer Wiring Diagrams. Below are the 7 pin trailer wiring diagrams for each of the three main types of trailers. Even if your wiring color codes do not match up with that of the universal color coding listed earlier, the functions of each of the wires (regardless of color) will still match up with the same pins in the wiring diagram.. Wire your trailer lights with our 7-way diagrams and walkthrough, or watch our how-to video.. Adding Standard 7-Blade Connector To Single Axle Box Trailer With 7-Way Round Pin Connector. Hey Chris, thanks for getting in touch. The plug in your picture is known as a 7-way round pin connector.. If you just need a 4-pin to 7-pin trailer.