Wiring my old boat...

[carlosg]

Hi guys,

I have an old ’89, 16' Larson Runabout All American 5000, it had an 80’s Johnson motor and I replaced it with a 6cyl. ’82 ELPT Mercury that had been in storage for about 30 years. Well, the boat has gone thru many owners thru the years and today I’m doing some TLC on it and it has come the time to work on the electrical, after gutting out all the trash left over after each time someone worked on it I now only have the gauges coming to the front panel wired by my mechanic from the side control harness; I’m going to install a Combination Fuse and Terminal Block to which I plan to connect the following accessories (when I can buy them all):

Marine Radio
Fish–Depth Finder (got one who knows if it works)
Navigation Lights (original on boat: front and rear)
Radio-CD…?
Cigarette Lighter for connecting Cell Charger
Bilge Pump (installed)
Compass (bought)

Thus I think feeding the Fuse Block from the battery with an 8GA Marine Duplex passing thru a 20 AMP Push Button Circuit Breaker installed at the battery well (in rear) and at the front connect the 8GA to the Block with a lower amperage Fuse Holder:

• What size Fuse do I need for all my “accessories” draw?
• Can I connect the Fuse Block to the 8GA feeder passing thru a Fuse Holder with a smaller GA wire?
• From the Block I will wire all of the accessories mentioned above with 14GA, each with its own fuse: what size fuse for each accessory?

Thanks for taking the time to read my post, any and all comments are deeply appreciated, I'm a newbie to the boat world and every bit helps!!!...

Note: the bold underlined text has hyperlinks

Mod EDIT: The links have been removed. The forum server redacts competitor links. Please check the iboats online electrical section for those parts. If you find it priced lower elsewhere, iboats offers prive matching. Thanks


BTW: Lots of stuff is currently on sale as part of The Great Fall Sale. Plus they offer a discount to forum members so ask about that too.

 

[batman99]

I recently rewired my Bayliner boat and did the reverse. re: Removed broken Mercury / Force 120 engine and installed Johnson 115 OB. For my setup, I did the same as well. re: Ran fused "-" and "+" set wires from rear position battery to the master fuse box under the dash. Then, I wired out each item from there. At the battery, I only fused the thick "+" wire. Think it was a 30 Amp ATC push in fuse holder with water cap approx. 8" from the positive battery post. Before going into master fuse box, I installed a HD toggle switch (on the dash). When this switch is OFF, all lights and gauges are off. The ignition key only runs the boat's engine and its key choke. For me, I draw a large diagram and applied the KIS method. re: Keep it Simple. Thus, reason for 12V HD toggle switch to run its lights and a different switch to run only its engine. When laying on your back and tracing wires under the dash and gunwales, a pen flashlight in the mouth and clear lens glasses (to stop crud from falling into the eyes) works best. And if you can, remove the driver's seat - to allow more access / comfort - while laying on your back. For good diagram and fuse details that might help, surf: http://www.12voltplanet.co.uk/fuses-guide-uses.html

Hope this helps.

 

[smokeonthewater]

You do not choose fuses based on draw, you choose fuses based on the wire.... The fuse at the battery protects the 8 ga wire...

Then each circuit off of the fuse box gets a fuse to protect it's wire...

10 ga, 14 ga, 18 ga, etc all need different fuse sizes....

Obviously you CAN use a smaller fuse but you can't use a bigger one than mandated by wire size...

Fuse size vs wire size is easily googled so I didn't include specifics.