Ummmmm, turn the pump off since it isn’t needed when connected to city water?
Water is an either/or situation. Water in the tank and no city water, use the pump. Connected to city water, pump is pointless since city water supply taps into the system AFTER the pump.
Even with the batteries disconnected, all of the 12v systems in the trailer still need power so your converter is supplying juice to the lights, refrigerator controls, water heater controls, furnace, operating tongue jack, slide(s), etc. This is a bad thing because the converter is not designed to do this. Batteries are required to absorb the surge loads these items draw and you can easily overload or burn out your converter if you don’t reconnect to the batteries soon.
Rob & Amy
2019 Passport 240BH SL
2015 Ford F150 3.5L Ecoboost SCrew 4x4 w/Max Tow Pkg