7-pin heavy duty connectors used on trailers, caravans etc. to connect the obligatory lighting (12N) and auxiliary power systems (12S) to the towing vehicle. Both connectors are similar in appearance apart from the gender of the pins, designed to ensure the connectors cannot be connected to the wrong socket.
Trailers, Caravans etc. - 12N connector used to connect obligatory road lights.
Caravans - 12S connector used to charge caravan battery, power fridge and equipment etc.
|Pin||Cable Colour||12N Connector Function||12S Connector Function *|
|1||Yellow||Left Indicator||Reverse Lamps|
|2||Blue||Fog Lamps (if fitted)||Spare|
|3||White||Ground||Ground for pin 4|
|4||Green||Right Indicator||Permanent 12V power / charge|
|5||Brown||Right Side / Taillamp||Spare|
|7||Black||Left Side / Taillamp||Ground for pin 6|
12N connectors are normally coloured black. Pins 2, 5 and 7 in the plug are female, others are male.
12S connectors are normally coloured white. Pins 2 and 5 in the plug are female, others are male.
Note that the 12N and 12S ground wiring must not be connected together and must be connected to the towing vehicle separately via the associated connector.
* 12S pinouts to post 1999 European standard. Pre-1999 caravans are wired differently, check a specialist caravanners website for details of this and more in-depth discussion of 12S caravan wiring.
Normally screw connectors. Thread the nut and glad onto the cable before wiring up the plug and fully tighten gland after assembly to provide strain relief and water resistance. Be especially careful to ensure there are no loose strands of wire as a short circuit whilst towing could cause a breakdown of the towing vehicle or lighting.