The original question was how to wire the breaker. There are many answers out there but none explain it simply and completely. I also would like to fully understand how to.
If you’re using the breaker that is in the link above. First get the appropriate sized crimp ring terminals for the breaker. Make a cut on the positive[Red] wire about 2 inches from the battery end of the trolling motor cable, this is where the breaker will be placed. Strip each end and crimp a ring terminal onto each. Now if you notice in the picture linked above there is a copper post and silver colored post, the copper post connects to the ring terminal nearest the battery, the silver post connects to the ring terminal going to the trolling motor.
Personally I would get one that mounts directly to either the battery post or boat instead of loose like the one linked. Less chance of short circuits.
BTW, DO NOT do as someone mentioned above and solder any connection that carries a heavy load like a trolling motor. They have a tendency to heat up and will loosen over time causing more heat that can eventually cause a fire. Only solder these types of connections if it is crimped as well. The solder will help protect the connection against corrosion
