The battery switch wasn't what I had in mind. I talked to a couple of my racing buddies at a local swap meet yesterday. It looks like a Sure Power 120 or 160 amp electronic isolator is what I need. My alternator is 135 amp output but I don't think there would ever be that much current going to the camper batteries. One of my buddies gave me a web address for an outfit,
http://www.towshop.com that has the Sure Power brand isolators. I think they are made in the USA.
One of my other buddies wires race cars so I think he'd be able to walk me through this project. Sounds pretty simple and that works for me.
I won't deal with Whitney after a problem with a misrepresented motorcycle seat i purchased a few years back.