7 pin adapter for 12S & 12N

Oct 9, 2018
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Hi.... my tow bar has a 7 pin socket on it .... my caravan has 2 7 pin soclets (12S & 12N)..... my predicament is that I can only use 1 at a time.... is there a way I can buy an extension/ adapter to use them both at the same time without converting to a 13 pin...?? Thanks


Mar 14, 2005
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In simple terms, no.

The socket you have on the car is the 12N (the black one) which supplies the running lights on a trailer or caravan.

To use the second plug, the 12S (the Grey one) you will need to supply a 12S socket for the car and wire it in, it supplies the power to the fridge and battery charger when the car engine is running, and also the reversing light on the caravan.

You do not actually need to convert to 13 pin, but is much more preferable to the two 7 pin sockets which ,particularly if running the fridge when towing, where there are high instances of centre pin burn out with the 7 pin socket.
May 7, 2012
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If you are upgrading the car to get the additional power for the fridge then it is probably worthwhile converting both the car and caravan to 13 pin plugs which I find far superior once you get used to them.
If you are not keeping the caravan for long though, a convertor from the twin plugs to the 13 pin type would probably be enough.
Jan 19, 2002
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As in an earlier stream the wiring is all colour coded and there are diagrams readily available via a search engine. If you would consider upgrading to a 13 pi system you are 'future proofed' if you change either car or van. On the caravan it would be worth taking a 13 pin cable back to the junction box to replace the grey and black. Currently you could strap the grey so that it doesn't drag on the road and connect the black - road lights will then work (except the reverse on the van if one is fitted), but you won't have fridge cooling or battery charging while driving.