Towbar Electrics: The Definitive Guide | Witter Towbars 7 Pin Towbar Wiring. 7 pin electrics provide the normal or legal lighting requirements for towing. A 7 pin towbar plug will provide brake, indicate and tail light functions on your bike rack, trailer or caravan and is suitable for simple towing. To help you understand how 7 pin towbar wiring works, our helpful diagram will help you Towbar Wiring Guides : Electrical Wiring Guide for Towbars : Towbar Wiring Guides . Listed below are some basic 12N and 12S type wiring diagrams that will help in vehicle wiring for both road lights and caravan internal electrics. Alternatively, we are willing and able to look at any wiring problem here at our workshops. WIRING DIAGRAM FOR 12N TYPE 7-PIN Black socket or plug for vehicle road lights Trailer Wiring Diagrams | Guides & Advice | ATE UK Apr 26, 2021Below we have the wiring diagrams for both a 7 and 13 pin connector. You can also watch a video where Glenn explains how to wire a 7-pin plug here. 12N Type 7-Pin Wiring Diagram. The 12N towing electrics (also known as single 7-pin electrics) are needed to run the lights on your trailer, caravan, or other towable equipment. ISO standards for trailer connectors - Wikipedia The 5-pin has a design and pin layout that is identical to the 7-pin ISO 1724 connector with the exception for the lack of pin 1 (L) and pin 4 (R). This connector is sometimes present on vintage vehicles and the actual wiring may be completely different from what the standard states which means that measuring before connecting is a good idea. Understanding the Leisure Battery Charging Circuit One of the easiest ways to check if the ECU has a specific output is to check the electrical wiring instructions that are supplied with a Ford factory wiring kit for 13 pin towing electrics. Usually the wiring diagram will have a lead from the coil side of a ordinary 30 amp relay going to a specific terminal on the main vehicle fuse board.