Trailer Wiring Diagram 12s. 12n normal electrics wiring diagram for the exterior lighting on a trailer or caravan from western towing. The12s socket is supplied by a seven core cable with grey sheathing.
The 12s socket is not always fitted to a car as if the car is just being used to tow. Click on the image below to enlarge it. This is currently the most popular plug used for towing as it does the lighting on most trailers and caravans.
Earth for terminal 2 and 4.
Click here or on the photos for more information. The table and diagram below explains the connections used on a 7 pin setup. Below is a diagram of a 12n trailer plug with coloured pins as they are wired. If you have a 13 pin socket fitted to your vehicle adaptors to plug in so you can use a normal 7 pin plug are available.