Wife took the horse box on a short trip and on returning could not uncouple the electrics and said there is a really bad smell from the back of the car.
The plug and socket are completely melted together. I cut the wires on the car and trailer and took it to the work bench.
I cut it down the centre with a hack saw and opened it up.
The trailer was fitted, from new with an adaptor, from 13 pin to 7 pin. and to be honest I have never examined it.
It appears the 7 pin part twist and locks in the 13 pin socket.
This looks like where the problem started.
As luck would have it only popped one fuse. With luck like that I might do the Lottery this week.
Regards Paul.