wire diagram-

I am new to wiring and electronics.
I am looking for feedback on this diagram I drew. It is a pretty basic setup: nav lights, LED spotlight, and 2 fishfinders. Please let me know if anything should change.

Also, what sized circuit breaker by the battery?

One more: the fish finders currently have inline fuses..should I leave those on or take them off if they wire to the fuse block ?

This chart https://www.engineeringtoolbox.com/amps-wire-gauge-d_730.html says to use 30 amp breaker, but putting a smaller one is is just fine too.
It is OK to have extra fuses in the isres, as long as they are sized properly for that branch's gage.

This is far from a strong suit for me. Just wondering. You are using a fuse block with, I assume, a variety of fuses between your battery and all of your equipment. Other than a way to isolate the battery, what is the purpose of the 20 amp circuit breaker at the battery?

I'm not saying it shouldn't be there. I am just curious because my similar set up doesn't have a master breaker at the battery.

The advantage of fusing a wire right after the power supply is that if there is any short (i.e. cut in the insulation) down stream, then you won't start a fire.

Doesn't happen very often, but if it did, would kinda ruin the day.

I used something similar to this: https://www.oreillyauto.com/site/c/detail/LIT0/MAH1/N1177.oap?ck=Search_fuse+holder_N1177_-1_-1&keyword=fuse+holder&pt=N1177&ppt=C017

CedarRiverScooter said:

The advantage of fusing a wire right after the power supply is that if there is any short (i.e. cut in the insulation) down stream, then you won't start a fire.

Doesn't happen very often, but if it did, would kinda ruin the day.

I used something similar to this: https://www.oreillyauto.com/site/c/detail/LIT0/MAH1/N1177.oap?ck=Search_fuse+holder_N1177_-1_-1&keyword=fuse+holder&pt=N1177&ppt=C017

Click to expand...

Shoot, that makes sense. Thanks.

Your diagram looks good to me, but I'm no expert.

Check where you show "12/14" gauge against this Marine Wire Size Chart, remembering to use the total length of the circuit (+ and -).

The circuit breaker should match the total amp draw of all the accessories. I prefer manual reset breakers over auto-reset so I know if there's a problem.

Many switch panels have the fuses / circuit breakers built into them. You probably do not need 12/14 gauge for any of that stuff, 18 gauge should be enough.
You may want to consider wiring up a 12v outlet / "cigarette lighter socket" and just plug a spotlight in when needed. You also have a aux 12v outlet for cell phone charging, portable gps, aerator, etc.. when needed.
Tim

The wiring diagram seems fine. As for the main circuit breaker, add up the max amperage of all the components in your system add 20% and that should be roughly your main circuit breaker. That breaker should be as close to the battery as possible, if not on it. The reason for the main breaker is to prevent dead shorts in the system usually caused by chaffing of the insulation in the wire before it has any chance to get to a fuse.

You need to add all your loads because you need it to be large enough to run everything at once.