by Redneck Teepee » Wed Jun 29, 2016 9:32 am
Your tank fill line should be a completely separate line. Your 12volt pump discharge side (pressure side) should have a check installed to let the pump flow when energized where it tees off for your shore supply it should have another check valve installed to let the shore supply flow as intended. In other words 2 checks installed to flow in opposite directions. Your 12 volt pump may have a built in check, but installing one will make double damn sure.
Hope I was of help

I fear the day that technology will surpass our human interaction, the world will have a generation of idiot's.