I have a 1997 Fleetwood Southwind 35' wide body 450/454, with two 12 volt batteries and I think there's an extra cable hooked up to the positive side of my motor battery. Having electrical problems ...
I was a certified RVIA tech, so I know how some of the techs are. I wish you the best tech support to get it repaired and get you back on the road as soon as you'd like!!!