How to wire a Rule automatic bilge pump: The 3-wire guide

All wiring on these pumps uses 28 inches of silicone-blocked wire, which prevents water from traveling down the wire if the insulation is ever nicked – an important safety feature for marine applications.

The 3 wires and their functions

• Brown: automatic lead – connects to the pump’s built-in float switch for automatic operation
• Brown/white: manual override lead – allows the pump to be run manually via a panel switch
• Black: negative (ground) lead

Recommended installation: 3-way switch

Xylem recommends connecting all three wires using a 3-way switch. A 3-way switch provides numerous benefits, including:

• Flexible operating modes – auto and manual control in one switch
• Manual override – run the pump on demand for testing or cleanup
• Service-friendly control – off position allows easy maintenance and system isolation
• Clear status visibility – supports monitoring of pump operation at a glance

Installing without a panel switch

On smaller vessels, such as rowboats or dinghies, a panel switch may not be an option. In that case:

1. Use only the brown (automatic) and black (negative) wires
2. Run the brown wire through a fuse rated to match the amperage printed on the pump before connecting to the battery
3. Seal off the unused brown/white wire using heat shrink tubing and silicone caulking

Important warning: do not join the brown and brown/white wires

Connecting the brown and brown/white wires together is one of the most common installation mistakes. Do not do this. Joining these two wires bypasses the automatic float switch and causes the pump to run continuously, which will drain the battery and can burn out the pump motor.

If you do not plan to use the manual override, seal off the brown/white wire – do not connect it to anything.