Most boats and POS coaches have a battery ON/OFF switch, which effectively disconnects the battery power from all circuits. It seems as if many conversions do not have such a chassis power switch. It occurs to me that it would be a good idea to put one in a coach if none exists in order to work on the electical system. The DC system in coach carries big amperage; at least it would be a great safety feature for the DYI kinda guy.