Maybe you folks are more knowledgeable on this subject than I am and I went through this maneuver for naught!Bothered me that selectable cabin accessories (water pressure, exterior/interior lights, stereo, etc) could not be switched hot UNLESS the main house batteries Master Switch was pointing to Batt 1, 2, or 1+2…at the same time "making the cockpit engine panel hot as indicated by live Voltmeter and ultimately all the sailboat wiring potentially HOT from bow to stern”….There was no actionable isolated main “ACCESSORIES SWITCH".
Picture #1: Notice my first finger and thumb with new added HD12V toggle main accessories switch for DC now “off" with big red main House batteries switch OFF (no Green service light)! That means 100% DC will be shut off bow to stern on the sailboat. (example: When leaving sailboat).
Picture #2: Now with toggle “on” thus the green service light is “on” and big red house batteries master switch is still “off”, all cockpit engine panel switches/voltmeter and multiple wires from distribution panel to cockpit and back are now inactive…only chosen cabin switches are hot (water pressure, exterior/interior lights, stereo, etc). NOW I HAVE A MAIN ACCESSORIES SWITCH !
When the new HD toggle switch is “ON”, service light is on and big red master house battery switch is pointing to Battery 1, Battery 2, or 1+2; then all 100% DC wires, bow to stern are HOT including engine (with key on), cockpit engine panel/voltmeter, all selected 12V distribution panel switches for instruments, interior/exterior lights/water pressure stereo, etc. are selectable.
NOTE: BILGE PUMP IS PROPRIETARY WIRED DIRECT TO HOUSE BATTERY BANK…ALWAYS ON.