Fuse Block - Basic wiring questions

[Peter simon]

I am going to add a gps/fishfinder to my boat shortly and while i am still figuring out which one, I wanted to get the wiring in order. I also dont know if later i may add additional items. While i have experience in home wiring and know the basics I have some boat specific questions...

This is for a 2019 190SX.

Plan is to run a negative from the battery and a positive from the battery switch. I am assuming i can just crimp a ring to the wire and put under the nut on the negative battery post and do the same with the positive but i assume the battery cutoff switch (1 battery) can accept the same ring crimp behind the switch. Are my assumptions correct?

Next i need to route the wires to the helm. Is there any preferred way to do this? How often should i secure them when routing them?

Next i was going to mount a fuse block under the helm. There seems to be a ton of space so I was just going to pick a high spot away from interfering with any storage etc.

Then when i add the gps, i just run the 2 wires to the fuse block with whatever size fuse the gps recommends?

Few general questions...

What size wires to use?

Is there a point where you have too much draw from the battery? Not that i plan on adding too many electronics do i add the amperage of the devices amperage together and compare to the alternator to make sure i am not overloading the electrical system? Do I even need to worry about this?

I know i will get a ton of recommendations for a dual battery setup...I have started reading the threads.

Thank you in advance. Any suggestions welcome.

 

[tdonoughue]

Howdy!

First, yes, you can do a ring crimp behind the battery switch and lump another ring on the negative side of the battery.

Routing: I opened the hatch to the gas tank, ran over/around that, and up to the helm area. I zip tied to existing lines or other convenient spots. Many folks will put the wires in loom along the way (keeps them together, protects rubbing wear on the wires).

Fuse boxes (like the one from Blue Sea, which I got) usually only handle the positive. So you will find a hub (which you will connect to the battery switch), spots for several fuses, and a screw for each fuse that runs to the component. For the negative part of the equation, you will want a negative bus bar (Blue Sea also makes these). I got a 4 stud one. Basically you run a wire from negative of the battery to the bus bar, then connect each component's negative to that bar as well.

Sizing: Sizing of the wires you need depends upon the amp draw and length of the run. See Part 1: Choosing the Correct Wire Size for a DC Circuit - Blue Sea Systems . Basically, you are going to add up what you have to attach to the bus/box, add some for what you anticipate adding someday, and run that size wire back to the batteries.

You won't need to worry about overloading the magnito in the boat. The magnito charges the battery, as you draw off the battery for your toys. If you have too many toys, you just wind up with a dead battery eventually, because the magnito will not fill as fast as you are discharging. Get a battery tender/charger for when you are not using the boat. Plug that in to charge. Until you start getting amps and things, that will probably do you. Many people when they put in an amp, etc. or just for peace of mind will add a second battery and rewire so that all of the accessories (stereo, GPS, etc.) go to one (the 'house') and the other starts the engines ('start'). Basically, that makes it so that even if you drain the one battery completely with your toys, you can still start (and begin recharging) and get home. To manage the 2nd battery, I recommend an ACR (see the Blue Sea Add-A-Battery Kit) (yes, I like Blue Sea stuff; no, I don't work for them or get a cut. but maybe I should...).

Hope that helps some!

 

[Peter simon]

Thank you. That was just the info i needed.