You can do it yourself if you are confident with electrics, it involves making a number of conections and fitting a couple of relays. Otherwise get it done at an outo electricians. If doing that you might consider going over to the modern 13 pin single plug that all the vans are fitted with now.
Brian
------------- there are 10 types of people in this world, those who understand binary and those who don't.
It is simple enough to fit you need a socket and mounting plate, charge relay, fuse and fuse holder and a couple of crimp connectors.
The wiring for the socket can be found here the Yellow attaches either to the reverse light or relay if fitted. then to wire the charge Relay use the This web page. The hardest part about this job is putting the power cable in. This to make it work properly I recommend that a high rated power wire is run direct from the battery (I use a 35 amp 4.5mm cable) this is well over spec but thin power cables can vave a voltage drop. the relay senses that the envine is running by the voltage increacing if a thin cable is used the voltage drop can cansel this out. the difficult but is threading the cable Through the car to the battery. I recomend that a 20amp fuse is fitted close to the battery to protect the cable from shorts.
I found the grey just a waste of time,afterall we only did use it for the fridge when travelling, then i thought, why carry food stuffs in the fridge when we can buy them when you get there.