We have a Conway crusader 2006. I have a 13 pin adapter on my car for the electrics. Since we had the camper we noticed when I plug the grey electric plug into the car and drive for a short while it will trip the relay on the car.
Do you need to have the switch inside the camper on the car setting, I think I had it in the middle. Could that be the cause?
what else other than the fridge is powered by the grey plug when travelling?
Unlikely on a lightweight TT/FC, but where fitted to larger heavier caravans, it also powers the Alko ATC stability system.
No expert on TT/FCs, but I believe similar switch on older caravans, switching between CAR-OFF-LEISURE BATTERY. More modern units are AFAIK auto sensing/switching.
If the centre position is 'OFF', then I don't see it being the cause of your problem.
One of the problems with older outfits/towbar wiring, is that the function of the towbar electrics has changed over the years, AND inevitably it will have been worked on/tampered with as well, so a degree of uncertainty exists with exactly what you have got!
Thank you, wiring diagram very useful. I agree dont think that’s the cause when it’s not switched. I’ll see if I can get a local caravan servicing to give it a check