member Pugwash, one red star [Online] Posted 10 April 2012 by Pugwash Quote | Report It does not matter what equipment your van has the wiring is exactly the same for twin or single sockets. The wiring system, for towing, should be identical on all cars. You added a further complication to question that wasn't needed. And besides, I never went into what wire in what pin did what in which plug/socket. All cars wiring is same except when your caravan is old enough to NOT have a habitation relay & then it's different. ;-) Write your comments here... The older caravans without habitation relays etc will have different wiring, however all car wiring should be the same no matter the age of the car. It may depend on the age of the van what charging voltage the van battery receives. This is the van system not the car system. Are towing sockets being checked in the car's MOT? Post liked!