ACC switch on Bass Cat control Panel – Second Bilge

I have the same boat (Classic) as you,  2019. For 4 years now, my boat sits in the water for at least 3 weeks while we are away at a cottage (in fact, we are away at the moment, my boat is at the dock, and it is pouring). I have had no issues in a hard overnight rain with the auto bilge being able to handle the water.

You likely know that the master power switch/breaker in the battery compartment needs to be on for any of the accessories wired through the boat’s harness to be able to function, including the auto bilge that is already there. I wired in compartment lights and tapped power from the USB port. I then supplied my own on/off switch for them under the dash.  But again, the master power in the battery compartment still has to be on for them to function. You could do the same kind of thing with a bilge pump. I think that the only way to install another bilge and not have to have the master power on would be to wire it directly to the battery, and, use your own on/off switch. Not hard to do.

I have p2 with 2 bilge pumps from the factory, they are both run off the same button on the dash.  When the float switch trips, or set to manual, they both come on.  My guess is they are both wired off the same switch.  May not need to use your accessory button.  Could check with Basscat and see if you could just wire them together on the same run/switch.