It depends on the year of car you intend to buy as the modern vehicles have can-bus technology which briefly is electronic messages delivered in milliseconds all around the vehicle. If this is so then the advice is to have the 13 pin socket otherwise it can sometimes cause some problems.
A 1990's caravan will have the twin 7 pin plugs fitted as standard (unless they have been changed to a 13 pin but it has been known to cause problems incorporating a single plug in replacement to the original two). For this you will need an 13 pin adapter to insert the caravan plugs in to.
If you have reversing sensors on the vehicle then you need the towing socket positioned so it is not detected.
Depends on the age of the car. If it's years old then cheap as poss I would have thought? Do you even need twin electrics? If you are not worried about running fridge or charging battery enroute then for cheap go for single 7pin socket.
If you are buying a 1990s caravan don't really expect fridge to work very well 12v while towing anyway so not worth the bother. If you are intending to use normal campsites then you will be hooked up to mains ehu onsite so that will charge your battery.
That's if caravan you buy has a battery which you don't actually need anyway on ehu provided transformer/charger has 2 position switch 3stage or float. Switch to float & will run 12v on ehu without battery in circuit.
Mind you only done 28k from new with fsg and is in mint condition. It was my grandads and has been sat on my drive for 2 years barely used as I have a work van that I use daily.
I will also be getting an old caravan like I said before.
I'm not actually sure what I need or will be using as I am new to this and just reasearching although I want to be using mains electric at sites.
I dont understand that last paragraph above suppose I should do some more reading
I would have just a 7pin socket wired in. On a car that age it should be a simple job. That will give you road lights for the caravan. On site you will be plugged into mains which will work fridge & everything else. You will of course have to ensure caravan electrical & gas systems are working as they should.
The caravan will have a second grey lead which you can stow out of way & just plug in black lead to towbar. If you want the second grey 12s socket installed on car then tht's going to cost more as it has to be wired through car to battery with relay. That will give you caravan battery charging you won't really need & 12v fridge which may be ineffective on 12v so not really worth it I would have thought?
I have a 1988 caravan and a 2000 car, and I have only a single black 7 pin socket. No problems at all. I am lucky enough to have the caravan at home, so I take a mains electricity supply to the caravan and switch the fridge to mains. I then fill the fridge before I leave home and keep the fridge door shut. Mains stays on overnight, so the battery is fully charged and the fridge is cold. The fridge stays cold during the journey, and I plug into the EHU as quickly as I can when I get on site. Never had a problem with any of the food, and my beer stays cold.
Personally, I wouldn't bother with the grey plug and socket, or fitting a 13 pin one.
My van will be in the drive and for the first few trips at least we will be travelling about an hour and a half to the coast. Also want to use use sites with electrix hook up and some facilities etc rather than basic pitches so I suppose the single 7 pin will be ok.
But what if I then buy a caravan that has a 13 pin?
All things being equal and if the cost difference isn't that much would a 13 pin make more sense then I can get an adapter to 7 pin?
Or for caravans that age is it going to be highly unlikely they are 13 pin
An old caravan will not have a 13pin plug unless one has been fitted more recently. They were not standard fit until 2009. In the unlikely event it has 13pin plug you can get a 13pin plug/7pin socket adaptor for few quid. You could always fit a 7pin plug on caravan anyway.
An old caravan fitted with 13pin plug is an unlikely scenario so if you get a 13pin socket on car you will most likely have to use an adaptor unless you fitted 13pin plug to caravan.
Just as a nod, pre-1997 caravans auxiliary (Grey plug)were wired differently to post 97 caravans so if you do fit a grey plug to your car make sure it is wired to suit a pre 97 van
PS the difference is in the battery charging & fridge circuits