Don't have this problem, but the electrical diagram i have shows there is a 3A Fuse at the Main Disconnect fuse area (C-153) BR wire with red tracer to bilge pump (that is energized whenever the battery is in) it is powered even when the main disconnect is in the OFF position.
Electrical diagram also shows there is a diode (C-220) between the Bilge Pump switch on the console and the Bilge Pump (in line on the BR wire. Don't know where the diode is, but guessing in the console?