My switch is set up so that with in the neutral position, the pump will automatically cycle with the float switch. The switch is spring loaded and when moved to the right, it over-rides the auto operationa and the bilge pump runs as long as I hold the switch and when I let go, its back in auto run. It works this way even if the panal dc switch of and even if the battery selector switch is off so it is clear that the power to the switch comes directly from the battery, before the battery selector switch. (By the way, this wire should have fuse protection).
I imagine your switch is wired the same way. If you want to test this, turn the dc power switch off, turn the battery selector switch to off then: Dump some water into the bilge until the bilge pump float activates and let it pump until it empties. Then hold the spring loaded switch over and listen for the pump. If it is working in both sitations, then your's is probably wired correctly. You can do all this with a volt meter but its just as easy to listen for the pump. If it doesn't work in either situation it is probably the pump, the wire from the battery to the switch, the fuse or the switch or a ground wire open. At that point a volt-ohm meter may be needed to check where you have the failure.
