Help with Very Basic Wiring Instructions

Skook

Seaman Apprentice
Joined
Apr 8, 2009
Messages
47
At the risk of sounding like an idiot, I would appreciate simple instructions on how to re-wire a very basic aluminum fishing boat. I bought the boat used, and the original owner did some type of D-I-Y wiring job that I would like to replace. I've looked at the diagrams here, but they are overly complicated for my needs. I have no electric start motor, instrument panels, horns, stereos, etc.

The previous owner cut into some type of thick, gray industrial-looking cable that has several individually insulated wires inside surrounded by some type of metallic shield. Where he cut it, he added terminal connections on each individual wire, which are then connected to the positive post of the battery with a bolt/wingnut. One uninsulated wire from inside this cable runs to the negative post. This cable is then connected to another piece of the same type of cable using a pinned connector with a screw-down collar. This section of cable is wired directly to an old, very rusted terminal block screwed onto the transom, and there are three or four fuses (5 amp glass-type) connected to this terminal block in a separate fuse holder.

All I really want to do is upgrade this wiring to run a fishfinder, navigation lights, and maybe some type of courtesy light. My bilge pump is a sponge and bucket, and I have no livewell. The trolling motor is run from a separate battery.

Having no experience, I am asking for opinions on what equipment I will need. The wiring itself should be simple. I've read enough here to understand the importance of using good tinned wire, making good connections, heat shrink tubing, etc. I'm just not sure what type of terminal block, circuit breaker/fuse panel, bus bar, etc. that I should use.

Thank you.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Help with Very Basic Wiring Instructions

Think of wiring as water running through a pipe. Electricity starts at the POS terminal of the battery, goes to a fuse or circuit breaker, then into a switch, then out of the switch to the device (light, locator, or whatever) and back to the NEG terminal of the battery on the usually black ground wire. Here is a diagram of a very simple light circuit. Replace the light with whatever device you want whether its a locator, accessory socket, etc. The arrows indicate the direction of current flow. 16 gauge wire is sufficient for most circuits on the boat except the red and black wire from the battery to the fuse panel. That should be #8 or for your simple electrical system #10 would be fine.

LightingCircuit.jpg


Here is another:

Basicwiring.jpg
 

Skook

Seaman Apprentice
Joined
Apr 8, 2009
Messages
47
Re: Help with Very Basic Wiring Instructions

Thank you, once again. I really appreciate your taking the time to go through this with me, and my kids will thank you too when I have them out on the water. I believe I can tackle this. Do you have any recommendations as to exactly which type of switch/fuse panel to use?

Does one of the switch/fuse panels such as a Blue Sea Weatherdeck eliminate the need for any type of terminal block? Should I use a bus bar to group all of my negative wires back to the battery?

The problem I am having is that all of the equipment that I can find being used in my Internet searches appears to be for more complicated systems. I would like to have an idea of what I need to purchase before taking on this project.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,537
Re: Help with Very Basic Wiring Instructions

Typically, you have a ground bus bar near your fuse block which is usually near your helm. You would then have one large ground wire that goes back to the battery or engine block. The size of this wire should be the same size as the positive wire that feeds the fuse block since it carries the exact same amount of current.
 

triman

Petty Officer 2nd Class
Joined
Sep 30, 2002
Messages
124
Re: Help with Very Basic Wiring Instructions

Even in the most basic of wiring setups, do NOT rely on the aluminium hull for your earth return!!! Unlike a car, your boat lives in an electrolyte, the water and having feral negatives running through the hull can cause no end of damage.
I've seen several hulls that looked like colanders by the time 12 volts had done it's bit.
 
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