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 Towbar Electrics: The Definitive Guide | Witter Towbars What are 12N and 12S? 12N electrics provide the 'normal' legal lighting requirements, via a single 7 pin electrics plug. These include the brake, indicator and fog lights. 12S electrics provide the 'supplementary', or advanced, electricals through an additional 7 pin twin electrics plug. To help you understand how 7 pin towbar wiring works Trailer Wiring Diagrams | Guides & Advice | ATE UK Apr 26, 202112S Type 7-Pin Wiring Diagram. The 12S type 7-pin electrics (also known as twin electrics), is a 2 plug system that combines the single 7 pin 12N electrics socket with a 12 S socket. The 12 S sockets are used where you need more power than ISO standards for trailer connectors - Wikipedia 7-pin trailer connector Type 12S (ISO 3732) 7-pin ISO 3732 trailer connector type 12S (Towing vehicle side) There are two main variants of the wiring with a switchover date 1999. The difference is that an additional connection for ground and that battery charging in the trailer is shared with other consumers. This means that if a pre-1999 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. The 13 Pin Plug Puzzle | Caravan Chronicles However I do think that the second page of the Menber instructions you’ve posted above are somewhat misleading as the diagram of the pin numbering in the context of wiring a plug would make you think that you could use this as a visual guide while wiring the plug, i.e. the lower right hand terminal on the plug is pin 13.