Wiring Diagram for 12N Trailer Plug

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The 7 Pin ‘N’ Type ( 12N ) trailer plug is used for supplying all trailer lighting excluding reverse.

This is the most popular Plug and socket used on trailers and caravans in the UK and Europe.

To view our range of 7 Pin 12N Plugs, Sockets, Extensions & Convertors: CLICK HERE

Over coming years this plug will probably be replaced slowly by the 13pin Euro plug.

The 13 Pin Euro plug has been used on Caravans since 2008.

From ( 29th October 2012) all Newly Manufactured O2 Class trailers require a Reverse light.

As a 7 pin plug does not supply Reverse lights this is usually done by using the 13 pin plug.

Many major manufactures have been fitting reverse lights and 13 pin plugs on O2 trailers for a few months before this date.

The 7 pin ‘N’ type (12N) plug will still be used on O1 trailers and many towbar fitters will still offer the 7 pin Socket as the cheapest alternative.

Wiring Diagram for a 7 pin 12N trailer plug.

Below is a diagram of a 12N trailer plug with coloured pins as they are wired.

On the rear of the pins the numbers are marked in the plastic next to each pin.

The pins usually have a small screw to retain the wire on the back.

7 Pin plugs fitted to trailer wiring looms regularly have spade connectors for quick assembly.

Trailer plugs with spade connectors are not widely available as spare parts.

If you have a damaged plug with spade connectors that needs replacing the spades can be cut off and the wires fastened in to the back of a screw type plug.

When assembling a plug always remember to slide any gromets and caps down the cables before you start to attach cables.

Which colour wire goes where in a trailer plug.

Following the Information below this shows the pin number in the 7 pin plug the colour wire that should connect to the pin as the diagram above and then states the trailer light that the wire should power.

7 pin 12N Trailer wiring Diagram
Pin No.Wire colourTrailer light Function
1YellowLeft Indicator
2BlueFog light
4GreenRight Indicator
5BrownRight tail / side Light
6RedBrake / Stop Light
7BlackLeft tail / side Light