Towbar wiring types0
The electrics on a towbar control the lights on the back of a trailer or caravan and also keep vehicle electrics secure and working properly, so it important for them to be installed correctly. There are many kinds of wiring, but in the UK Single electrics and Twin electrics are the most common.
Standard single electrics – 12n,
Standard single electrics (also known as 12n) are the standard single electric fittings on many towbars, it is also the lowest requirement of wiring required by law to tow. However it does come with some restrictions on usage.
These kinds of wiring are made up on one electrical socket consisting of seven pins and are either fitted under the bumper or a car or beside the towball. This socket allows you to run your road running lights for your attachment such as a trailer or it’s lighting board.
The socket uses its seven pins to power / control different things, which are, Left hand flasher, Earth, Right Hand Flasher, Right Hand Tail Light, Left Hand Tail Light, Fog Light and Brake light. Each controlled function is linked to a specific pin which is associated to a colour. You can usually find out colour or pin coding information from the place your towbar is from, however it will be wired by your fitter at or after the time of purchase. This kind of wiring, as you may have noticed leaves no pin to connect a reverse light, which is allowed as they are not required by law, but some people do find them to be helpful.
Twin electrics – 12s
Twin electrics are similar to single electrics, as they have the same functionalities which make it legal to tow, however twin electrics add functionalities to your car that are not a legal requirement for towing, but can be beneficial for some drivers. Each of these extra features is also connected to a pin and colour on the board.
The benefits twin electrics add are, Battery charging, caravan interior light works, reversing light and fridge workings. The power to things such as fridges and caravan lighting tend to be cut off when the ignition of the vehicle is turned off, meaning it only works when the towing car is running. So a main permanent feed is needed from either the vehicle’s battery or a fuse box.