Below is a diagram for the original plug and socket showing the functions of each pin. I had one vehicle with a 12 pin socket and a trailer with a 7 pin connector and they played happily for years.
Seven Steps To A Successful 7 Pin Trailer Cord Plug Repair
Wiring a 7 pin trailer socket. On older trailers theres sometimes a 5 wire setup using a 7 pin connector. This supplies power to the road lighting of your trailer or caravan. This type of connector is normally found on utvs atvs and trailers that do not have their own braking system. The 7 pin n type plug and socket is still the most common connector for towing. Trailer wiring diagrams trailer wiring connectors. Note that this type of 4 pin connector is less common that 4 pin flat connector.
There is a standard method of wiring a 7 pin trailer connector. Includes guides for 7 pin 6pin 5 pin 12 pin 13 pin pin and heavy duty round plugs and sockets. Trailer electrical connectors come in a variety of shapes and sizes. Above we have describes the main types of trailer wiring diagrams. In the trailer wiring diagram and connector application chart below use the first 5 pins and ignore the rest. By law trailer lighting must be connected into the tow vehicles wiring system to provide trailer running lights turn signals and brake lights.
This has now been replaced by 13 pin euro plugs on all new caravans. In these cases exclude connection for right tail light 58r and rear fog light 54g and connect the tail lights only to pin for left tail light 58l. If your truck has a built in 7 pin socket but you only need 5 of the pins. Various connectors are available from four to seven pins that allow for the transfer of power for the lighting as well as auxiliary functions such as an electric trailer brake controller backup lights or a 12v power supply for a winch or interior trailer lights. If you dont follow this your trailer or tow vehicle cant be used with any other implement. The basic purpose remains the same whether your truck and trailer is using a 4 way 5 way 6 way or 7 way connector.
Below is the generic schematic of how the wiring goes. I used a small 7 pin round for 10 years and then after replacing the plug multiple times changed to 7 pin flat for the last 15 years and i have never had a problem with a flat connector. Electrical system includes harness with 4 pin connection point for plugging in a brake controller wiring adapter sold separately supplies required fuses wire taps and additional hardware. Use the 7 pin connector anyway see below and just leave out the last 2 wires. Install a 7 way rv style trailer connector on your vehicle with this easy to splice harnessmodulite draws power directly from the battery to avoid overloading your vehicles circuits. The 7 pin connector uses on newer trailers all 7 pins according to the iso standard.
4 pin trailer wiring diagram. A colour coded trailer plug wiring guide to help you require your plugs and sockets.
Gallery of Wiring A 7 Pin Trailer Socket
