How many of us are there? Owners of Dodge based RV's?

>Negative of which battery?

Both are grounded to the frame.

>How did he deal with the constant power need of the radio to maintain time and presets?

Mine was wired by the PO to one of the fuses on the fuse block in the glovebox right next to the radio. The radio ground is fastened to a screw in the firewall.