"""Hopefully, you have an ON/OFF bilge pump switch ONLY, and do not have one of the Manual/OFF/Auto helm switches.
FYI and FWIW for you guys who moor your boats, and may have the Manual/OFF/Auto helm switches!
You DO NOT want a helm located Manual/OFF/Auto bilge pump switch.
These require the MBSS (main battery selector switch) to be ON, plus the Manual/OFF/Auto switch must be left in the "Auto" mode in order to provide float switch power.
Our main engine bay bilge pump's float switch should be powered via an Un-Interruptible power supply, and from the largest Amp Hour battery bank.
You can power this from the rear MBSS terminal #2 (house bank), fusing the circuit appropriately.
Your On/Off ONLY helm switch will over-ride the float switch function if need be."""
What in the world is all of that SPEW???????????????????????? and the ridiculous graphics to boot!
Uninterruptible power supply..............Aside from you, who else would use such language and who else would know what that means?
OMG...............Of course I know exactly what it means but a simple boat owner would not.................KISS .....................moron.
most likely reason fuse blew is pump running all the time when it should not.
What you need to do is figure out how it is wired.
Go to bilge pump switch (at dash board) and see how it is wired.
How many wires are going to it and how many positions does the switch have? (is it an ON/OFF 2 position or OFF/ON/ON three position).
Once you let us know we can then determine how it may be wired.
Question? Why would you need the KEY ON to test or use bilge pump? The bilge switch MUST be wired to battery + 12 Volts. Not to ignition ON.