looking for Aux battery wiring info, 92 Eurovan Westfalia Weekender


New member
Recently acquired a 92 westfalia weekender (private sale), and found the auxilliary battery was not charging. Was told by the previous owner that she usually disconnected it in the winter (why, I don't know).
So, things I've tried, in chronological order;
I tried a long drive to charge it by the alternator, didn't work.
I tried using the 120Vac trickle charger in, and it popped the GFI outlet (behind drivers seat)
I opened the panel in back and saw both the trickle charger and battery, and while there were a number of smaller gauge wires disconnected, it all seemed in decent shape, though I verified with a meter the battery was completely dead (less than a volt!)
So I opened the adjacent panel (under the fridge) and saw a real mess of burned out wires, especially the line to the battery charger. (footnote, the previous owner told me she recently installed a new battery, and a local RV company installed a new charger. While the wire from the charger looked great, what it tied into was a catastrophe. Which is why I'm NOT taking it back to the goofs who installed this nightmare)

The burned out wire (looks like the ground overheated, the white and black conductors were ok) runs from the breaker/switch/GFI panel behind the driver's seat, and appears to connect the trickle charger to an external AC source via a relay. Anyway, in that circuit only the interconnecting cable seems to have melted, but it's fused to the backside of the cabinet so I have to remove the fridge/stove,sink to get it out to replace. :-(

But there's also been some collateral damage to some of the adjacent wiring harness, which is proving difficult to find accurate information on. These are smaller gauge wires that I suspect provide monitoring signals to/from the module above the rear-view mirror.

I'm interested in doing this correctly, as it's possible whoever did the work previously made a catastrophic mis-wiring. I'm adept at schematics and general electrical, if I could find good information I would be eternally grateful. Anyone here able to help me out?