Thank you, everyone, for the suggestions. I believe I may have solved the problem.
The battery tray on this new-to-me coach, makes it difficult to see the furthest interior battery. The positive and negative house leads are connected to the furthest front of the 3. While cleaning up the tray, I removed all the batteries and discovered a second set of positive and negative house leads connected to the innermost battery. My last rig had only one set of leads connecting the bank to the coach. My wheels began to turn.
Isolating the negative lead from the front battery appears to cut power to the 12V system of the house. But I discovered the bank was still receiving a charge after pulling that negative.
So it seems a little more than likely that the Xantrex has its own, separate leads between it and the bank. Therefore, by pulling the outer negative, I should be cutting power to the coach while maintaining power from the Xantrex in any charge mode... including Equalize.
Thanks again,
K
Cheers,
Kendall