"Tim Watts" wrote in message
...
On 06/03/17 19:16, NY wrote:

I've seen some cars with two 7-pin connectors and I presumed that the
second was for the things like permanently and switched live and
reversing lights. What is odd is that my parents had our caravan (Lynton
Javelin - how do I still remember that name) in the early 70s, I'm
*sure* we only had one 7-pin socket and not a second one. OK, I was
about 10 at the time, but I was at an age when anything "different"
stuck in my mind. Maybe I've mis-remembered.

As a kid who grew up caravanning I can add some authority to this:

12N was the "basic" connector. Most people only had that. It had one
permanent live for supply.

Really? http://www.towingandtrailers.co.uk/shop/132/133/142/ doesn't mention
permanently live. Have some of the pins been "re-purposed" over the years?
If you plugged a modern caravan into an old car or an old caravan into a
modern car (all with 7-pin) would you get some strange results like fog
lights permanently on or fridge only coming on if car's fog lights are on?