This is, I believe, the NATO wiring for a "Sankey" socket. Also given are the colours to match a "Standard" 12 way socket.
[Pin A] Red/Brown = wire #1 = Convoy = not used on 12N
[Pin B] Green/Purple = wire #2 = Stop = Pin 6 / Red
[Pin C] Red/Brown = wire #3 = Convoy = not used on 12N
[Pin D] Black = wire #4 = Earth = Pin 3 / White
[Pin E] Red/Orange = wire #5 = Tail = Pin 5 (RH Tail/Brown) & Pin 7 (LH Tail / Black)
[Pin F] Red/Yellow = wire #6 = Fog = Pin 2 / Blue
[Pin H] Red/Brown = wire #7 = Convoy = Not used on 12N
[Pin J] Green/Purple = wire #8 = Stop = Pin 6 / Red
[Pin K] Purple = wire #9 = Aux = Not used on 12N
[Pin L] Black = wire #10 = Earth = Pin 3 / White
[Pin M] Green/Red = wire #11 = LH Indicator = Pin 1 / Yellow
[Pin N] Green/White = wire #12 = RH Indicator = Pin 4 / Green
A,C & H are joined together, as are B & J and D & L
K auxiliary is a permanent 12v feed, but a triler won't need that (unless you plan to have some work lights on it, or run a fridge etc)
the Nato sockets and plugs....
890.061DT Nato Socket and Leads @ £75.00
560483 Nato Trailer Plug with Leads @ £52.50
are available from
PA Blanchard and Co.
You may also need a crossmember reinforcing kit to attach the towing mechanism - pn KNK100090K. Or just the Packing Plate and the Stiffener Plate which are NRC8323 (Stiffener Plate) and 531447 (Packing Plate) depending on your rear crossmember.
useful link