That's a tricky one, cos there is quite a bit of stuff behind that fuse. To me it sounds like rubbing wire also. For sure I can tell it's not the cooling fan, fuel pump, drl or the output sockets because those have their own fuses. I'd check the trailer socket and all the moving wires like on the handlebar. There's nothing I can see that would relate to driving 35miles and turning on then. Many engine components take power behind the main fuse like injectors, coils and o2's, so none of them can be the culprit.
Front diff motor is having power from that fuse. Could it have something to do with it?