Kevin,

Wow…the world’s greatest site for boat wiring ever…thank you for your contribution to the boating world!!!!

Here we go…2002 Harbor Master 440W. Flip on the navigation lights at either helm, up or down, and within 10 seconds…pops the breaker and no nav lights.

I own a Multimeter…damn fine one at that…but have no idea how to use it, where to start or what to do to chase this down. Thought I would take the logical approach…hire the boatyard to fix…but they have had the work order now for 7 months and have just not had a chance to get to it.

I know I can chase this problem down with your professional guidance.

Help.

Warmest Regards…

Walt

Hi Walt,

First:

• Test the breaker.
• Check the rating on the breaker.
• Remove one of the wires from the breaker.
• Connect one of your meter wires to the open breaker tab and the other to the wire.
• Select AMPS on your meter.
• Turn on the switch.

If the current that trips the breaker is less than the breaker rating, replace the breaker.

Second:

• Reconnect the breaker.
• Most individual navigation lights draw less than 1 amp. Remove one of the nav light wires from either nav light switch (gray/green for nav lights and gray/blue for anchor lights). Connect your meter using the same method used above.
• Turn on the switch. Do this for each output wire on each switch. This will determine which wire has the short.

Once your determine which wire is causing the breaker to trip, follow the wire to the light it is associated with. The problem will be between the switch and the light.

You should be able to determine which wire is causing the problem in a few minutes. Finding the short may take a while, but it will be a simple fix.

Let me know if you have any questions,

Kevin

Hello,

First off…..Let me say, that I have enjoyed reading through a ton of posts on your site. You perform a great service, and knowledge is power.

I am going to be adding a trolling motor soon to my 191 CC Mako. The trolling motor is a 24 volt model. I would like to add two Group 31 deep cycle batteries for the trolling motor, and have one dual purpose battery to crank with. Three batteries total.

I would also like to pull 12 volt power leg out of my 24 volt series to power accessories and act as a house battery when I am not using the trolling motor, and an emergency crank battery.

I have included a wiring diagram that I drew up. Please take a look at it for me.

What concerns me most is the 12 volt ground coming off one of the batteries in series. Have I done this right? I thought this problem might be a good one to discuss on Easy Ac/Dc.

I have found no answer to this on the internet yet. I would be happy to update this diagram per your recommendations and give you the corrected one in the end, if you would like it.

Thanks,

David

Hi David,

Very nice schematic.

I would suggest some minor changes.

I would use battery A instead of battery B as your paralleling battery. Basically you would be paralleling to your 0 to 12 volt battery instead of your 12 to 24 volt battery. This will create a common ground in your boat wiring and help reduce stray current corrosion and accidental mis-connected grounds.

After you switch your paralleling switch to be connected to battery A, pay close attention to 12 volt devices that you may connect only to Battery B. If their ground wire comes in contact with any other ground wire in the system, it will create a dead shore across Battery A. You may want to consider installing circuit protection in the ground wire of any 12 volt item that you connect only to battery B.

Your bilge pump “manual on” switch needs to draw power from the same fuse as your bilge pump “auto” switch. You should only have a single source of power for any device. I would keep the switch at the helm, but run a wire from the auto bilge fuse (load side) to the line side of your bilge pump switch.

Make sure your wire sizes are appropriate. When your cranking battery switch is in the parallel or trolling motor battery position, the cranking circuit will include the wire from the switch to Battery A. Battery A to your Ground buss. Ground buss to Battery C. These wires should be at least the same size as the main engine battery cables.

Let me know if you have any other questions,

Kevin

Hi Kevin,

First of all, thank you for all of the time and effort that you put into your website. The boat wiring information that you share is invaluable.

So tell me Mr. Marine Electrical, do my ambitions exceed my abilities?

My wife and I have a small sailboat that we’ve enjoyed for many years. It’s a perfect size for the two of us and can’t imagine anything that would make the boat more fun…with one exception. We find that we are very jealous of our marina neighbors who have shore power. Whether they are using a television, a drink mixer, a vacuum, a toaster, or even a simple battery charger, we start down the “if only” path.

How tough a project is it to add AC power to an older boat? I’m reasonably comfortable with simple household wiring jobs, but have been told that marine AC can be an incredibly complicated and – if not done correctly – incredibly dangerous.

Any suggestions?

Thanks.

Matt

Hi Matt,

No project is too big, not project is too small when “Mr. Marine Electrical” is on the scene!

Seriously, there is a great new product from our partners at EzAcDc that will fit your needs. They have a complete marine shore power system that follows their snap-together philosophy of simplifying boat wiring jobs.

Installation of the new marine shore power system is easy.

The panel is pre-wired and comes with a remote outlet with 10′ of boat cable that simply plugs into a “snap together” plug on the back. The kit is also pre-wired with 10′ of Marine grade boat cable that runs from the boat AC panel to the included shore power inlet.

Best of all, any complex electrical connections are already made inside the powdercoated aluminum box.

All outlets are GFCI protected. And, for additional safety, the AC panel has a dual pole breaker to protect the boater if the dock outlet is wired backwards.

The panel also includes a power “on” indicator light and a reverse polarity light. It also comes with the AC to DC grounding wire that is required by the US Coast Guard. This wire runs from the back of the panel to your DC negative buss, engine ground, or battery negative and provides an additional safety path to ground if you have an AC fault on your boat. Even though required, this wire is redundant on this well-designed system since the GFCI also protects everything.

Additionally, there is a single outlet on the back of the shore power panel to allow a built in AC device to be connected. This is ideal for a battery charger or refrigerator that comes with a standard 15 A household plug. Simply plug it into the back of the panel before installing.

It comes with the industry standard 30 amp Marinco inlet. You can choose between the standard square plastic inlet or upgrade to the stainless steel version. Both will connect to an 30 amp marine cordset or adaptor.

Please let me know how your project turns out. I always like pictures.

Kevin

Hello,

I have recently bought an early 80s 22 ft Chrysler sailboat. The electrcal system is bascalliy non-existent.

I am starting from scratch and want to add a DC system that is capable of accepting shore power. Initially I am only interested in adding basic navigation and communication system and some lighting. However, I do want the system to be expandable and capable of accepting shore power or a portable generator.

I have no idea what I need to start with. Can you please provide some suggestions?

Will

Hi Will,

Our partners at EzAcDc have a great system solution for you.

You can combine their Fully Wired Marine Switch Panel with one of their Deluxe Boat Wiring Harnesses to make a complete system for all of the items you have listed.

The switch panel will control navigation/anchor lights, courtesy lights, and 2 accessories. It includes a voltmeter so you can monitor your battery condition. The boat wiring harness has wires for split red/green forward navigation lights and a single white stern light. It also provides wires for a courtesy light. The additional switches can be connected to other devices such as VHF radios and GPSs.

For the future, connecting marine shore power is not too difficult as long as you as focus on safety. For small systems, you always want to use GFCI protection and the DC ground is connected to the AC ground. Always look at the worst case and make sure a breaker will trip before somebody gets a shock.

The two biggest problems with portable generators are carbon monoxide generation and AC grounding. The best way to connect a portable generator to a small boat is through the shore power connection with a long cordset (keeps CO away from sleeping area). When making your electrical connection, make sure the AC neutral is connected to the AC ground on the generator.

Please let me know if you have any questions,

Kevin

Kevin,

Thanks for the fast reply and I think both the products you reccomend will work great for my boat. But I am still unsure about the shore power connections and the battery charger I would need?

Will

Hi Will,

Besides a battery charger, what other AC devices do you plan on adding to your boat?

Kevin

Kevin,

Whatever cord I would need to connect the battery charger to shore power, a bilge pump (or maybe two due to my boat’s design) and a stereo and a fan.

Will

Hi Will,

I would seriously consider using a battery charger like the Guest 2608A combined with a Connect Charge Inlet as your shore power system. The charger has a standard extension cord plug on the end that snaps into the back of the connect charge inlet. The connect charge inlet mounts through the deck of your boat. You can plug a conventional extension cord into this inlet.

The rest of the devices on your boat can be DC and run off of the battery.

This approach will save you several hundred dollars on your shore power system while achieving the same results.

One of the next EzAcDc items will be marine shore power systems for a small boat. It will include an AC cabin panel, a 30 amp shore power inlet, multiple outlets and cabling. It will also provide a means of connecting a battery charger and a refrigerator. This kit will be on the market for around $300.

Please let me know if you are interested in this type of kit and we can work a discounted deal in exchange for installation photos.

Thanks,

Kevin