if you want to know which each pin does, a google search is your friend.
Most of the electrics can be taken from the wiring that goes to the rear light cluster.
the big concern will be a split charging cct. This makes sure that the cars battery is fully charged before the car charges the caravan. If this is not a concern it makes life so much easier.
is this of help
http://www.watling-towbars.co.uk/wir...g_towbars.html
macafee2