thanks, I guess my main question was about the diode.
again, I got new batteries after the others ones got discharged and died. it's always humorous to read responses of those who did not understand the post.
disconnecting the panel was useless until I got the new battery bc dead battery would go dead again on it's own. oops, I had to park the vehicle at the storage place so could not run simple obvious test without endangering new batteries. My gosh, what a moron I must be. Oh, well, maybe next time I can dedicated all the hours in my day tending to the RV so I can do these easy test. well, thanks guys for the info, I can narrow my search when I get to visit the RV in it's parking place. I use a floor jack to load the batteries in, right now they are in my garage. To load them they go under the siding, up to clear the lip on the battery box that is attached to the frame under the floor, then down in a snug fitting cradle all while I lay sideways in an awkward position. I can't really see the terminals after this so connecting them is lots of fun. It's not something I want to do every 5-6 years, much less several times a day. I can't take the floor jack to the storage place though, so doing it by hand is a nightmare. To leave them in the RV means they will lose charge naturally until I get the system working again, to keep them here means it is impossible to track down the source of the drain. There is no outlet to plug in a charger at the storage place, and my covenant at home prevents me from storing an RV here. I wish I could do these simple test where u do this, then check back a few hours later, but checking back is sometimes a few days, in which time I would lose another set of batteries. So, there are the real details I guess...