If you look on the back of cars that Tow caravans you will see 2 sockets, one is for the normal lighting system and the other (normaly with a white or grey cap 12s) these are for the auxilary items in a caravan and carry thicker cables to cope with the heavier demand.
Terminal 6 & 5 on the one with the white cap is the 12v supply No6 being the possitive cable.
On the Ordinary (12n) socket, there is NO 12v supply, the earth is terminal 3,
Pin 1 = left indicator (yellow wire) marked L
pin2 = Fog Lamp (Blue wire) marked 54G
pin3 = negative return (white wire) marked 31
pin4 = right hand indicator (Green wire) marked R
pin5 = Right hand Tail Light (Brown wire) marked 58R
pin6 = Stop Lights (Red wire) marked 54
pin7 = Left hand Tail & number plate Lights (black wire) marked 58L
If you want the details for the the auxilary sockets Just ask.
