Thank you all, and especially Scott and Doug. My only intent in this post was to help/inform other members of some things in the charging and battery systems, but it seems to be the other way around - I'm getting informed.
I'll check again with my owners manuals and call Winnie (I'd love to get schematics for the coach). Perhaps a relay or other electronics only connects the alternator to the coach batteries when they are a 1/2 volt low like one post suggested.
Perhaps there is something wrong with the dash switched battery boost relay, too. It did nothing the time I tried to use it when the chassis battery was low and the coach batteries were fully charged.
I passed on troubleshooting this because I can jump the batteries with a cable and the relays are a whole lot of work to get to.
In any case, thanks again. Great info.
