Note that the way this is hooked up... everything coming off of the right side is NOT protected so any kind of short over there means melted wires and smoke. That includes the green wire and the black on the bottom.
The big red going left is likely your house 12V supply to the inside power/fuse panel.
I had a mess like this but using a single breaker on the frame under the front end on my 2604WS with added lines for each of the two slides and the power hitch :-P
It is not there anymore :-)