I need some help please. Just set out on a trip to Scotland. First time away from home where it was set up by the man who delivered it. 2018 model I think. A 420. All was worki g at home but no electricity. Have I missed the master switch? Lights are OK but maybe 12v? I thought the fridge was working but not certain. All switches are facing the same way on the fuse box. And ehu connected correctly as far as I can tell.