Boat Wiring with Marine Grade Components

Have you ever wanted to rewire or add a battery switch, fuse, fuse block or circuit breaker on your boat? Well a few things to remember; use quality components and read the specifications of any component you are installing. If you are adding a trolling motor, depth finder, or lights always check the manufacturer’s recommended wire and fuse size.

An example of modifying your wiring to meet the manufacture specifications was when I installed my new trolling motor from a 28 lb to a 50 lb. First I needed to increase the wiring size from the batteries to my battery selector switch from a size 10 to 6 gage. Wire size or gage number works opposite of what you may think larger the number smaller the wire. My original trolling motor wire was 10 gage rated for 15 amps and the new trolling motor required 6 gage rated for 40 amps. The chart below shows how many amps per wire gage per feet of wire for a 12 volt DC system. In my example the data is based on a 17′ boat. You can double the wire length with the same amperage for a 24 volt DC system.

My battery switch was manufactured by Blue Sea Systems (TM) which are specially designed for marine use.
A switch is a nice addition to your boat. I had a battery die on me on a windy day and my boat was about to hit a pontoon and all I had to do was to turn the switch and select my other battery, then pull away. Always use a good quality Lug or butt slices with dielectric grease. Dielectric grease is a unique, non-curing compound used for sealing, protecting & electrical insulating. Just coat the wire before crimping the wire connector. You can always purchase butt splices with heat shrink tubing for extra protection from the elements.

By using the components designed for marine use and taking the time to make good connections and always installing the correct fuse for the wire gage and device you are protecting. You will never lose valuable fishing time trying to figure out why your depth finder, trolling motor or whatever electrical device you need stopped working because of loss of power.