Thanks for all of the help, but I am still looking for my missing bird. When I say looking, there is a difference between looking and seeing. I was blinded in my left eye by an inept retinal doctor in Las Vegas and I have Fuchs Dystrophy in my right eye. Neither of these are good. I have taught electronics and helped GM solve the original 'check engine' light issue when they first put a computer in their cars, so I really have fun tracking down things. But now I'm doing it with some difficulty. I am getting straight 'A's' in my braille driving classes, however
To solve the problem I could do a couple of things:
1) I have 14.4 volts from the engine at the emergency start relay when the motor is running. All that I need to do is just put jumper on the emergency start relay so that the engine would charge the house batteries while I am driving. I have used this kind of a jumper in the past so that when I was on shore power, the converter would charge house and starting batteries.
2) I can also easily install a normal RV isolator which is nothing other than a set of large diodes, but I guess I would like to fix the original problem with the Lex. (When you use a diode, you have a forward voltage drop of 1.1 volts so if the alternator is putting out 14.4V you end up with 13.3V at the house batteries. Better than nothing)
3) Buy a 100 amp diode and use that from the engine hot lead to the house batteries. (Same problem as 2)
Here's a picture of the DC disconnect relay and the emergency start relay in the house battery compartment. The emergency start relay is on the bottom with the right hand side being a 'hot' lead to the engine start battery. Left side is the house batteries.
Thanks for the help,