Small Boat Electrical System Overhaul

[Beerspitnight]

I want to install a VHF Marine Band radio, a chart plotter, and a SONAR, as well as an audio system. What parts will I need to do this re-wire?

Should I stick with one dual purpose battery and have that run all of my electronics as well, or should I install a starter battery and a deep cycle battery?

Beyond the runs of wire and connectors, what other equipment do I need?

A battery switch?

A new fuse box?

A new power bus negative or positive?

I'm not overly sure what the difference is between a fuse box and a bus. I'm sure the inclusion of fuses is a main differentiating factor, but I am not sure why one would use a bus over a fuse box.

Anything else?

Thanks again for your insight and suggestions.

The backstory: I wish to price a re-wire of my 1989 Montauk 17. I have had electrical problems with the [combined sidelight lamp] on the boat since I bought the boat. I have concluded that the most likely [cause of the problem] is the corrosion of the wiring to the lamp. I called up a buddy of mine who is an electrician and asked him to re-run those wires. I also just purchased a used [white all-round lamp]. I figured I would ask him to hook-up and check the wiring for the [white all-round lamp] while he was there. Then I started thinking: If the electrician is coming out to re-run the [wiring to the bow] and to hook up the [white all-round land], why don't I just ask him to rewire the entire boat? Costs might be the reason to not do the re-wire, and that is where I need your advice.

The battery is currently under the reversible pilot seat (RPS). I don't like it there. I have plans to put a new fuel tank under the RPS, so I would like to move the battery. My first thought was to move the battery back to the stern. I would get a new battery box and strap it down at the stern. Then, I started reading more about putting the battery in the console. I know the owners' manual said not to do this. I did a search of this forum for "move battery from console to stern", and I didn't get any hits. However, I did get a ton of hits for moving the battery from the stern to the console.

If I am going to move the battery to the console, I will and should run new wires from the battery to the engine.

[jimh]

There is no need to hire a commercial licensed electrician or a boat yard electrical installer. Electrical work on small recreational boats is not covered by any regulations or electrical codes; there are only recommended practices. The American Boat and Yacht Council (ABYC) recommended electrical practices is a good reference. See

https://law.resource.org/pub/us/cfr/ibr ... 9.1990.pdf

If you do hire someone to perform the work, you will have to get an estimate of their labor costs from them.

What parts will I need to do this re-wire?

For general work on boat electrical systems you will need:

--primary power distribution bus wiring accessories for positive and negative primary power distribution

--marine grade wire in various sizes with distinctive insulation colors

--ring terminal connectors for various wire gauges with various hole diameters

--crimp tooling to install the ring terminal connectors

--insulated wire clamps to support the wiring

--an assortment of stainless steel pan head Phillip head self-tapping screws in various sizes and lengths to use as fasteners

--proper wiring tools such as wire cutters, wire strippers, hex drivers, and so on; I have a portable electronics tool kit; it weighs about 50-lbs; and I have drawers of additional tools I use all the time; it is hard to know exactly what you will need;

--usual hand tools, battery operated drill, very good assortment of drill sizes

For primary battery distribution wiring, see:

Dual Battery Wiring
http://continuouswave.com/whaler/refere ... ttery.html

For wiring of navigation lighting circuits, see:
Navigation Lamp Wiring
http://continuouswave.com/whaler/refere ... witch.html

For wiring of sump pump and float switches see:
Cockpit Sump Pump
http://continuouswave.com/whaler/refere ... ePump.html

For wiring of outboard motor starting circuits see:
Electric Starting Circuits
http://continuouswave.com/whaler/refere ... Start.html
and
Ignition Switch Wiring
http://continuouswave.com/whaler/refere ... witch.html

For information on the proper insulation colors to use for particular circuits, see:
Marine Wiring Color Codes
http://continuouswave.com/whaler/refere ... rCode.html

For repair of wiring to the combined sidelight lamp at the bow see

Q4: How Do I Repair the Wiring for the Combined Sidelights at the Bow?
http://continuouswave.com/whaler/reference/FAQ/#Q4

For an overview of the three levels of electrical power distribution on a small boat, see

Boat Electrical Circuits and Wiring Practices

This article presents recommendations for small boat 12-Volt direct-current (DC) electrical circuits and how they should be wired and installed. Electrical 12-Volt DC circuits on a small boat can be considered in three segments: primary power distribution, secondary power distribution, and branch circuits

For a short article and narrative of my own recent project to improve the electrical system on my own boat, see

Secondary Power Distribution Refurbished on c.1990 Whaler
http://continuouswave.com/ubb/Forum6/HTML/003179.html

Here is the primary battery power distribution wiring on my boat:



LEGEND

1: Engine cranking battery; Sear-branded Platinum Diehard Marine AGM battery 1,000-MCA.

2: House battery; Sear-branded Platinum Diehard Marine AGM battery 1,000-MCA.

CB1: Circuit breaker, 50-ampere, for distribution to electrical panel at helm console, original with boat, E-T-A brand, push-pull actuator.

F1: Fuse, 10-ampere, for distribution to aft sump pump control panel for pump in cockpit live well.

F2: Fuse, 50-ampere, integral with electrical harness from auxiliary charging output from E-TEC engine.

F3: Fuse, 5-ampere, integral with electrical harness from AC-operated battery charger for positive lead, cranking battery.

F4: Fuse, 5-ampere, integral with electrical harness from AC-operated battery charger for positive lead, house battery.

F5: Fuse, 5-ampere, integral with electrical harness from AC-operated battery charger for negative lead, house battery.

AC-operated Battery Charger; dual output, 120-VAC operated charger, 4-ampere charging each bank.

S1: main battery switch, BLUE SEA SYSTEMS 5511e Dual Circuit OFF-ON-EMG primary battery switch. The normal operation is for the Main Battery Switch to be in the ON position. This supplies the outboard motor MAIN harness with power from Battery-1 for cranking; after engine start this circuit supplies charging current to Battery-1. The outboard motor AUX harness supplies charging current to Battery-2 after engine start.

The Sump Pump Panel is supplied 12-volts from the HOUSE battery via F1. This permits the sump pump to run even if the main power switch is set to OFF. This allows the pump to evacuate water if the boat is left unattended, without having to leave all circuits powered.

Wiring of the primary battery circuits is done with 4-AWG or larger conductors, except the feed to the HOUSE panel is 8-AWG. The negative terminal of Battery-1 is the negative common point. (Note: this could more properly be moved to a heavy gauge bus, which would reduce the number of connections at each battery negative terminal. The bus would then become the negative common point.)

The AFT NEGATIVE BUS provides a convenient wiring point for the negative leads of several loads located in the stern of the boat. These loads receive their positive feed from switched circuits at the helm, but their negative leads return to this bus. Having this bus at the stern avoids having to run all these circuits back to the helm for the negative return. The circuits are:

--aft navigation lamp
--aft cockpit live well sump pump
--trim gauge isolated ground
--electric fuel primer pump
--aft cockpit pump control panel lamp circuit

The trim gauge isolated ground is provided to improve calibration of the trim gauge meter and isolate it from other negative return currents.

The BLUE SEA SYSTEMS 5511e switch (follow hyperlink for more information) is a dual circuit battery switch. It has only three positions: OFF-ON-EMERGENCY. The switch has separate circuits for two batteries, one nominally the engine starting battery and the second the boat house battery for non-engine loads. The two batteries are kept isolated at all times unless the switch is put into the EMERGENCY position, when the batteries are paralleled.

The change to this isolating switch was made to keep the boat electronics from being affected by engine starting in normal operation. I can have my GPS receiver-chart plotter-SONAR unit running, and when I start the E-TEC engine there is no effect on the battery voltage to the electronics. Nothing reboots due to a voltage sag. Also, at night, if we need to run the cabin lights for several hours, all of the drain comes off the house battery, and the engine starting battery is not affected in the least.

I made this change prior to our 8-day cruise to remote Isle Royale National Park, where we anticipated we would not have access to shore power at most of our overnight docks or anchorages. I did not want to have to worry about running down the starting battery if we left the cabin lights on too long, or have the chart plotter reboot at every engine start.

Here is a picture of my primary battery switch and the aft negative bus:



Regarding what sort of wire to use, see

Marine-Grade Wire: A Price Survey; Recommended Sources
http://continuouswave.com/ubb/Forum6/HTML/001447.html

Regarding where to buy wire and how much it costs: I have purchased marine grade electrical wire from GENUINEDEALZ.COM. I found their prices to be lower than most, the service was very good, the wire they sent was of excellent quality, and much of it was marked with the ANCOR brand name. See

http://www.genuinedealz.com/?sck=75633544

[Don McIntyre - MI]

I think that your making an excellent decision in considering a total rewire of a 25-year-old boat, especially if it's spend considerable time in saltwater or if it's gone through multiple owners. Some owners (or installers) think nothing of using low-grade speaker wire and cheap automotive connectors or worse yet, AC wiring parts and connectors.

You've already alluded to one of three main questions; one battery vs two, and inside the console or not. The third is re-wiring with fuses vs a circuit breaker panel (and if going with a breaker panel, how many circuits, back lighted or not, waterproof or under a cover, etc...). Do you want to maintain the classic look with the standard cylindrical fuses?

I can only speak from experience; almost all my Whalers either came with two, or I installed two, in the console. There was some concern regarding the off-gassing of the console mounted battery that could collect within the console. I don't think a standard Montauk console is that airtight to make this a concern.

Number of points:

--If you go the console route, best to cut open the console floor to allow the battery box to sit directly on the deck You'll have to reinforce the floor, as the console floor brackets are not strong enough to hold a battery. BTDT.... Added benefit is additional cubic inches gained with the batteries almost flush with the console floor.

--Seriously consider installing a battery switch.

--Stick with marine grade wiring and connectors. Blue Sea is a product line that a number of forum members have used and recommended.

--Don't tape a connection, either crimp or for a really secure connect, solder and crimp. Some of the best Blue Sea crimp connectors allow for heat shrinking of the splice connector.

--Is your electrician experienced in DC voltage, or is he a AC home or office electrician. There's a not so subtle difference.

--Are you using the boat in a way that would need a deep cycle battery or would two of the same (but separated by a battery switch) suffice? Like needing or using a trolling motor, for example.

--One important concern regarding the main leads from the engine to where ever you mount the power; avoid splicing into, or adding onto the existing cables, since the splice(s) would reside in a wet wiring tunnel. You may need to fabricate two new heavy gauge cables from the motor to the console. Something to keep in mind...

The amount of wiring beyond a Montauk console could be limited to the bow and stern lights, bilge pump, maybe an external light or two, and wiring from the motor to the console. What's time consuming is the actual wiring and the thought process of layout inside the console.

Aside from a spool of cable(s), you'll be looking to price: battery switch, connector block, breaker panel (say between a five and seven circuit panel), waterproof breaker shell (if using a non-waterproof breaker panel), some heavy gauge wire and oversize connectors (if the existing motor wiring will not reach).

My breaker panel has eight circuits: running lights, anchor light, compass, electronics, bilge pump, courtesy lights, instruments, spare.

Do it once, and do it right....

Jim is the go to source for wiring, so your in the right forum!

Regards - Don

[jimh]

Your inquiry is extremely broad. I recommend at this point you start new threads for various sub-topics to get specific advice. I suggest these topics:

--best location for engine starting battery on small center console boat;

--best wiring and installation practices for battery primary power to engine; (It may not be necessary to renew this topic as it has been discussed at great length. See many prior discussions.)

--recommended number of batteries and type, size, brand, and model of batteries for small boats (It may not be necessary to renew this topic as it has been discussed at great length. See many prior discussions.)

--recommended battery switches, automatic combiner relays, voltage sensitive relays, battery chargers, and other battery management practices

--recommend VHF Marine Band radios and antennas

--wiring accessories, tools, wiring connectors, fittings, and other electrical-related devices used for small boat wiring

If all of these topics are mixed in this thread, there will be too many overlapping conversations and topics

[Beerspitnight]

Thank you for the responses. I understand there was a lot going on in the post, so I appreciate your willingness to address those items.

Thankfully, my electrician buddy works for beer and boat rides. He is a union electrician.

Don - I am not sure if I need a deep cycle battery. I will not run a trolling motor. I will run the vhf, chartplotter/sonar, and audio system while not running the boat, so I feel that a second battery would be a good idea as I don't want to be stuck somewhere with a dead battery.
Perhaps a second battery would compel me to place the batteries in the console.

Thank you for outlining the items that I will need to complete the rewiring.

You've already alluded to one of three main questions; one battery vs two, and inside the console or not. The third is re-wiring with fuses vs a circuit breaker panel (and if going with a breaker panel, how many circuits, back lighted or not, waterproof or under a cover, etc...). Do you want to maintain the classic look with the standard cylindrical fuses?

I like the idea of having a clean looking circuit breaker panel. I am not sure how many circuits I would need: instrument lights, nav lights, vhf, sounder, audio...
I would place the breaker and battery switch in the console, so I don't think it needs to be waterproof.

Jimh - thank you for taking the time to describe the wiring situation for your boat. I am not skilled in electric, so I appreciate your precise instructions.

[Don McIntyre - MI]

Circuit breaker panel inside the console is hard to get to, I'd recommend a waterproof outside, either on dash or side mount.
You could probably combine the VHF, sounder, GPS, and audio system on one circuit, labelled "Electronics", to save space.
Don't need a deep cycle, just a second battery, with primary battery switch like Jim's.

Regards - Don

[jimh]

For small boat electrical power, using circuit breakers adds a lot of expense. Circuit breakers are typically not designed to work as circuit power control devices. If you want to use a circuit breaker as a power control device, like a switch, you have to buy specialty circuit breakers. If you want them to be exposed to weather, you have to buy specialty circuit breakers.

A much simpler, much less expensive approach for distribution of power on a small boat and control of the power is to use fuses and switches. The fuses are located on a central power distribution panel and kept protected from weather. The switches are on your helm dashboard and are designed to be operated thousands of times and to be exposed to weather.

I do not recommend trying to fit a big-yacht approach to electrical system design onto a 17-foot open boat.

[Beerspitnight]

Great. Thanks everyone.

I have no desire to add complexity to this rewire job. I was simply showing my ignorance of electrical systems by saying I would use circuit breakers. :)

Central power distribution panel it is.

[jimh]

Regarding switches on a helm panel to control electrical devices, I have only four:

--navigation lighting control: OFF, ANCHOR, UNDERWAY; classic push-pull three-position special switch; implementing this circuit control with a single circuit breaker would be impossible;

--compass and gauge illumination: ON, OFF; classic push-pull switch

--cockpit sump pump: AUTO, OFF, ON (Momentary); toggle switch; again, impossible to implement circuit control with a circuit breaker; and,

--NMEA network power: AUTO, ON; illuminated toggle switch.

All the other devices are operated by their own power switch. And there are not that many devices:

--outboard engine: OFF, RUN, START; specialized key switch;

--outboard engine safety lanyard switch; specialized lanyard operated switch;

--VHF Marine Band Radio: OFF, ON (plus volume)

--chart plotter: POWER; pushbutton switch; also, to have a switch that controls power distribution for this circuit is not a good idea; if you shut off power to the chart plotter circuit with the external switch without first powering the chart plotter down, there may be a risk of loss of data; the chart plotter is really a computer system, and most have a shutdown command; I would not want to just routinely yank the power from the chart plotter without having first run the shutdown command and letting it turn itself off.

Except for the outboard engine primary power, all the power for these devices comes from a secondary power panel at the helm. The outboard engine primary power is controlled by the main battery switch. (See above for details.)

If you want to preserve the classic appearance of your Boston Whaler boat, continue to use the classic Cole-Hersee push-pull switches that are original equipment on almost all Boston Whaler boats through the 1990's.


Cole-Hersee Special Purpose Push Pole Switch

There is also one unused classic push-pull switch on my helm panel. I have not found anything for it to control. Maybe I will add some cockpit lighting, and then this last switch can finally have something to control.

In the cabin there are two reading lamps; they are controlled by their own switches. In the aft deck compartment there is a second toggle switch for controlling the live well sump pump.

[Beerspitnight]

Thank you, again, for your help with all of this.