Help reviewing my boat electronics

[tobiasg]

Hi all,

I'm looking at cleaning up the electrics on my new boat and want to have some extra eyes on my proposed setup. I'm pretty new to boating so forgive my if I'm asking stupid questions or lack some of the correct terminology.

Here's the setup:

• I have a single battery (it's a small boat so no fancy starter and deep cycle setup as I only plan to run a few small electronics of it)
• I have a isolator switch right after the battery to turn everything off
• After the isolator switch I have the positive go to the engine and the other way a fuse to protect the rest of the circuit
• Next + buss bar leading to switch panel, fuses then lights/bilge pump
• GPS/Fishfinder does no go through the switch panel as it has its own on/off switch
• The bilge pump sensor leading again to the bilge pump is not behind the isolator switch so it will run even if electrics are tuned off
• Finally everything leads back to the - buss bar and back to the battery

Hope the above intensions make sense and would love to have people throw stones at it.

I know the Amps (thus fuse size) I need for my GPS/fish finder from the manual but I know I need to figure out the fuse sizes for my other electronics still, then have cables correctly sized (rated more than the fuses) based on that.

I guess the main questions I have are:

• Is the above ok?
• Am i right in not putting a fuse for engine starter?
• For battery to engine what gauge cable should I use?
• Should the negative from the engine go through the - buss bar or can it just go straight back to the battery?
• Any other tips/suggestions also welcome

 

[longjohnsilver]

I’m no electronics expert but that looks ok to me. However I would have the GPS wired to the switch. If you forget to turn it off you’ll come back to a fl battery. Can’t comment on wire gauge to engine as you don’t say how large the battery or engine is. And certainly no fuse between battery and starter.

 

[tobiasg]

Yea I'm still looking through manuals for the engine to get to grips with whats needed there but I'm sure that will guide me on that side of things. I do have the GPS/fishfinder after the main isolator switch which I would turn off every-time leaving the boat so that should make sure I don't come back to a dead battery but there is the risk I forget so possibly something on the dash like a indicator light to show the main circuit is live could help remind me.

 

[Mr Googler]

What outboard is it? Should be able to find the spec for battery cable size.

I would go straight to the battery for engine ve-. A lot of amps can travel down the engine to battery cables. Then run a separate smaller gauge cable for ve- busbar. Save you some money on heavy duty battery cable runs too.

2.5mm 30 amp marine tinned should be more that enough for battery ve- / after isolator ve+ to the electronics busbars. Just don’t keep adding kit….which is very likely ???

 

[tobiasg]

Just don’t keep adding kit….which is very likely ???

Oh man looks like you caught me before I caught myself ?

Yea mooching around the boat to see how it's currently setup the cables go straight to the engine starter so was thinking to do the same ?

The engine itself is an inboard nanni 2.60 HE and I'm digging through old grainy manuals now

 

[Mr Googler]

extranet.nannidiesel.com:8081/Joomla/index.php?option=com_content&view=category&id=72&Itemid=97&lang=en

some workshop manuals and installation stuff there. You’ll have to copy and paste the link above.