Bilge Pump Hard-Wired to Battery?

Hey guys-

I recently bought a 2004 V21- my first boat. The boat is wet slipped and stays in the water all the time.

The previous owner said that the bilge pump was hard-wired to the batteries (it's got 2) and the float switch would kick on when water accumulated in the bilge. Sounds like a good idea- I shouldn't have to worry about accidentally draining the battery by leaving the courtesy light on or something. The owner's manual confirms that the bilge pump is hard-wired to the batteries.

BUT- I was mucking around in the bilge this afternoon and lifted the float switch to make sure the pump would come on. It didn't. When I switched the battery from OFF to 1, 2, or Both and lifted the float switch, it purrs to life.

Any thoughts? Should I be leaving the battery switch on?

Nate