120 to panel but nothing works

I had a very similar incident when we were in Texas last spring. I had 120 at the panel, but every time I tried to operate something with it, the 120 disappeared. I checked all the internal 120 circuits for shorts and loose connections and they were all ok. I finally checked the shore power cable, where it connects in the junction box. I found that vibration had worn the wire nut insulation on the neutral and it was grounded to the box. Since it was after dark, I made temporary repairs and our 120 was working again. I made proper repairs to the connections the following morning.



When I opened the junction box, this is what I found.