Wiring Diagram for my build

I'm very much a novice when it comes to electrical, but I've read a lot here and other places and I'd like to get my wiring diagram critiqued. Please tell me what I'm missing.

The squiggly lines on the wire means in line fuse. The switch panel is a SeaSense 5 Gang with 12 V Power Point.

One question I have is where to put the 20 amp breaker? Should it go after the battery switch or between the battery and switch. There will be a second battery on the switch, but it will be dedicated to the trolling motor (with it's own 50 amp breaker) so that's why it isn't shown.

In total I'm coming up with a 15.07 amp power draw so I will be using 8 AWG b/c of the length of run (battery will be under the bow deck). Everything else will be good on 16 AWG except the Power Point which i will have connected with 12 or 14 AWG.

Thanks for any help you can give.

The breaker/fuse needs to be between the positive lead on your battery and the main power lead going into your switch.

Just finished a similar project with mine and the best advice I can give is to go with the better connectors and wire so you are going it right the first time.

If you have a real marine grade battery selector switch, I would wire it direct to the battery. Place your fuse or circuit breaker between the battery switch and the positive buss bar. Having the fuse/circuit breaker at the battery may cause corrosion and failure of the fuse/circuit breaker. Your battery should be in a battery box with cover, in Wisconsin it should be insulated to keep the battery from cycling cold to warm when not in use. I like the 8AWG wire to reduce voltage drop. For items off the switch panel they can be 14 AWG. Always use stranded wire, finer strands the better. Use crimp connectors with really good tooling. Think about changing running light bulbs to LED. You didn't draw your charging system. It should be wired in to the battery select switch, terminals should be there just for that. Don't have the motor running and turn off your main switch, without the battery as a load the charging system can go overvoltage and burn out your electronics; another reason not to fuse at the battery. For open connections exposed to the elements, Fluid Film is one of the best to use. Never ever spray WD40 on your electrical, it absorbs moisture and causes corrosion.

Keep this in mind, I'm no expert. I'm more like you and have done a lot of research.

I think the main breakers/fuses should be before the battery switch because I belive I read it is some sort of code to have the main breaker/fuse within 7 or 7 1/2 inches of the battery. I also think your fish finder shouldn't be on a switch on the panel. The reason I have read is that it goes through it's own start up and shut down so it needs to be turned on and off at the unit. It still needs a fuse inline to protect that wiring.

Someone please tell me if I'm correct.