Grey Pin Problem - Help!

moulesy

We have a conventional twin electric tow bar on our car, but a modern single electric socket on the van. So we use one of those two way connectors when towing. But we have now had two "burn-outs" on the grey connector (think it's called the 12S?). The guy who came to replace the socket said he didn't think it was a common problem.

 Has anyone else had this happen or does anyone know why it may be happening? Our van is in for service in a couple of week's time so it would be good to now any possible explanations before I ask them to investigate.

 

Thanks for any help.