Electric trolling motors provide a quiet and convenient way for boat owners to cruise slowly in shallow waters without running the main engine. Many trolling motors have clip-on battery connectors for easy installation and removal, while others might be wired into a foot control with a plug. Whether the boat has a 12-, 24- or 36-volt system, the best way to keep the wiring and motor from damage involves installing a circuit breaker between the battery and the motor. Installing a manual set, or automatic thermal set circuit breaker, will protect the motor and wiring from a sudden voltage overload. A boat owner can use a few simple tools and steps to install a circuit breaker on his boat.
Match your circuit breaker to your trolling motor by reading the specifications in the trolling motor manual for the trolling motor amperage. If in doubt about the needed amperage rating for your circuit breaker, purchase one that has a 40- to 60-amp capacity. Obtain a manual set circuit breaker if you wish to push or flip a reset button on the breaker for reactivation. You can obtain an automatic thermal set circuit breaker that will reset itself after a set time. If you must use additional wire to connect the circuit breaker to your battery system, make sure the wire gauge matches the existing trolling motor wire. For example, use 10-gauge wire for a trolling motor that has 10 gauge.
Turn the boat ignition key to "Off" and use a socket and ratchet wrench to remove the negative battery cable from the battery. If the boat has a 24- or 36-volt system, remove the negative cable from the last battery in the series. Look for a convenient location to mount the circuit breaker. Most breakers have two small mounting flanges, and you will need to mount the breaker as close to the positive battery terminal as possible. Likely locations are high on the inside of the transom or on a solid stringer on the gunwale. Do not mount a circuit breaker in the bilge or low on the deck.
Use a small drill bit to scratch the mounting hole location through the flange of the circuit breaker. Use a drill and a 1/8-inch bit to drill two small pilot holes. Use a screwdriver to screw the circuit breaker flange bracket to the surface. Cut the positive, red wire to the battery, so that both ends will reach the terminals on the circuit breaker.
Slip shrink wrap onto both ends of the wire and push it back out of the way. Strip both ends of the positive wire and twist the ends. Insert two eyelet wire connectors on each end and crimp them secure with the wire strippers. Attach both eyelets to the circuit breaker terminals and tighten the terminal nuts with a small socket. Push the shrink wrap up to cover both ends of the connections, and heat the wrap with a lighter. Reconnect the negative battery cable with a socket and test the operation of the trolling motor.
