To wire a 12-volt trolling motor, run the motor’s positive (red) lead through a manual-reset circuit breaker to the battery’s positive terminal, and the negative (black) lead straight to the battery’s negative terminal, using the wire gauge and breaker size your motor’s manual specifies for the cable length. A plug and receptacle at the bow lets you remove the motor, and crimped, heat-shrunk ring terminals keep the connections tight and dry.
What you need
- Marine-grade stranded copper wire in the gauge your motor’s manual lists for your run length.
- A manual-reset circuit breaker sized to the motor maker’s specification, mounted close to the battery.
- Ring terminals sized for the battery studs, adhesive-lined heat shrink and a proper crimper.
- Optionally, a trolling motor plug and receptacle so the motor can come off the boat.
12V trolling motor wiring, step by step
- Disconnect the battery or switch it off, and keep the motor switched off.
- Plan the route from battery to bow, away from fuel lines and sharp edges, and measure it.
- Mount the circuit breaker near the battery on the positive side.
- Run the positive wire from the battery’s positive terminal to the breaker, then from the breaker to the bow.
- Run the negative wire from the battery’s negative terminal to the bow.
- Fit the receptacle at the bow, or connect directly to the motor leads, matching red to positive and black to negative.
- Crimp and heat-shrink every terminal, secure the cable along its run, then reconnect the battery and test.
Why wire size matters
A trolling motor draws high current for hours. Wire that is too small for its length drops voltage, so the motor runs weaker and the battery seems to die early, and it can overheat. Longer boats need heavier wire; motor makers publish charts by cable length for exactly this reason.
The circuit breaker
The breaker protects the wiring and the motor from a short or a stalled prop. Use a manual-reset breaker rather than an automatic one, so you notice when it trips, and size it to the motor maker’s specification.
24V and 36V systems
Higher-voltage motors run from two or three 12V batteries wired in series, positive of one to negative of the next. In Minn Kota’s range, 55 lb thrust motors such as the Riptide Maxxum 55 ($899.99) are 12V, while 70 and 80 lb motors such as the PowerDrive 70 ($1,169.99) and Terrova 80 ($1,899.99) are 24V. See how to wire a 24 volt trolling motor and 12V vs 24V trolling motors.
Keeping it charged
Good wiring only helps if the batteries are healthy; see how to charge a trolling motor battery, lithium battery chargers and trolling motor battery life. Browse motors on trolling motors.
More guides: boat battery switches.
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