Re: Starting from scratch
Few boat manufacturers provide electrical diagrams on any of their products. As such, rewiring boats is sort of a black art.. As was mentioned, a factory engine manual will be helpful to a limited extent-like hooking up either a trim gauge or a tach, but not much else. Most boats today have a main wire harness of 10 or 12 gauge wire running from both battery posts to a main fuse block on/under the dash. That main wire may be fused back at the battery or at the fuse block. Almost all boat type accessories and gauges are typically wired from/to the fuses on that block. That includes the fish finders, horn, gauges, radios, bilge pumps, running lights, etc. Wiring this way eliminates the need to wire through the engine's start switch-that switch has a small fuse and won't handle all that amperage. You don't want to blow an engine fuse due to an accessory overload and find the engine won't start out on the water. Take a little time and you can work your way through it.
