please note., the switch is run off magnets, if you clean places where you can pick up little metal shavings they will build up on the switch over time. simply unscrew your switch once you have drained your tank, check it out and see if its fuzzy with metal shavings, if it is then clean it off and reinstall. then fill your tank with fresh water and check to see if it works. if it doesnt you might have a bad switch, but if it was covered in stuff it was probably just the junk in the way.WTF?? My van was sitting level today and started spitting out dirty water. What good is a shutoff float if it doesn't work?
hope this helps.