The plug most likely DOES NOT conform to any "standard." Very much like my Palomino.
My 2000 Palomino uses a standard 7-pin RV plug, but the wiring is COMPLETELY different. This was a complete surprise when I went to pick it up, and I ended up hauling it 150 miles home with one working turn signal, which was the only wire that matched up. It was a miracle that I did not get pulled over.
I had to use my jumper pack and a couple of nails to probe the various pins to determine which pin made which light(s) light. Once I established ground, it was fairly straightforward. Then I wired up an adapter cable to run from the 5th wheel plug in my bed to the camper. They also make "power probes" now for just such a purpose.
BTW, my camper has NO provision for an onboard battery, and never did.