How to Wire a Bilge Pump to a Switch

You can install bilge pumps two ways. You can install both pumps on the same level or you can install the backup pump higher than the primary pump. When the time comes to pump water, there is usually debris floating, and damage can occur to the pump's switch. Installing the switch too low is a disaster waiting to happen. A broken switch won't turn the pump on when you need it.

Things You'll Need

  • 10-gauge wire
  • Wire stripper
  • Crimp butt connector
  • Adhesive shrink tubing
  • In-line fuse holder
  • 15-amp fuse
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Instructions

    • 1

      Get the pump wiring out of the bilge and run the wires up the wall, securing them with a staple gun so the ends never touch bilge water.

    • 2

      Strip the inside wires of the 10-gauge wire down no more than a ½ inch with a wire stripper. Attach the ends to the screw terminals of the switch. The black wire is hot, the white wire is neutral and the copper wire is the ground wire.

    • 3

      Check the mechanical and electrical connection at the pump leads. The tape on the pump leads needs to be watertight. Use crimp-on step-down butt connectors to connect the 10-gauge wire to the pump leads and then use adhesive heat shrink tubing to make the seal watertight. A heat gun will shrink the tubing over the wire, creating a seal.

    • 4

      Make a direct connection with the battery -- do not run the pump wire through the distribution panel. You don't want the bilge pump to be without power when the boat is unattended.

    • 5

      Add a fuse to the positive wire and make sure it is positioned as close to the battery as possible. Use an in-line fuse holder and crimp the fuse holder into the positive wire. Insert a 15-amp fuse.