Easy Ac/Dc

Boat Wiring and Marine Electrical

Boat Wiring Questions?


Questions about marine electrical? Easy Ac/Dc has the answers.

Whether you are in mid-project or just curious, there are loads of posts on the site to check out. If you’re trying to track down more specific marine wiring info, please use the search box on the right or check out the list of various subjects farther down on this page.

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Thank you for visiting. We look forward to hearing from you and hope that you will be able to come back often.

Self Lifting


Hello Easy,

I came across your site somehow and thought I would send a question.

If I can get my boat onto my lift next year, I am wondering about different ways to power the ac shore station hoist mortar without shore power. Is there an economic way to utilize the boats batteries or use an inverter, or a very small generator that could be on the boat? Last year I left a portable generator on the dock, but I would hate to get it stolen and am just hoping there is a way comparable to using a dc motor (which I don’t have). boat lift motor

My boat is less than 3000 lbs and the motor presses against the wheel to rotate it.

Thanks.

Brian

Hi Brian,

It is amazing how low the lakes were last summer. Hopefully they don’t drop too much more.

The most economical solution would be to buy an inverter just large enough to run the AC motor on shore station. The shore station should either have a wattage rating or a current draw (watts=current*120).

Running the inverter for a short period of time to lift your boat should not be enough to completely discharge your boat’s batteries. If your boat has a battery switch, I would make sure it is not in the BOTH position when you are using the hoist to help prevent draining both batteries.

IMPORTANT; If your inverter is not ignition protected, do not run it in the engine room

Hope this helps,

Kevin

Cord Cutting


Hello Easy,

I am installing a new battery charger, a Guest Intelligent Charger, on my Irwin 25.

The new charger has an AC Plug and of course in the instructions recommend plugging into an AC receptacle protected by a GFCI breaker.Wire stripper

Is there any good reason or regulation, ABYC or other rules that would preclude me from removing the AC plug from the charger and terminating those wires directly to a dedicated breaker in my AC distribution panel?

The bulkhead where I am locating the new charger does not have a whole lot of room and I can save wiring real estate if I do not install an outlet. The run from the new charger to the AC distribution panel is no more than 2’.

Thanks.

Hi Andrew,

There are no ABYC regulations against hard wiring. In my opinion, it is safer to have a charger hard wired into the panel than to have any outlet in the engine room. You have no idea what other, non-ignition protected items may get plugged into the outlet. Also, GFCI outlets should not be used in an engine room because they are not ignition protected.

But, before you cut the plug off, I would make sure the charger works. You may void your warranty if the plug has been hacked.

Hope this helps,

Kevin

Aluminum Fuel Tank Grounding


Kevin,

I am told a copper ground wire should never be connected to a aluminum gas tank. Is that correct. I ask because my new tank has a ground tab welded on it.

Thanks.RDS aluminum fuel tank

Captain Ron

Hi Captain Ron,

Copper wire – either tinned or not tinned – is the marine standard for boat wiring.

When grounding a metal fuel tank, the main requirement is to keep the resistance between the fuel tank and the boat’s ground to one ohm or less.

Here is ABYC standard H-24 says:

“24.16.1

Each metallic fuel tank and metal or metallic plated component of the fuel fill system, which is in contact with the fuel, shall be grounded so that its resistance to the boat’s ground is less than one ohm.”

Hope this helps,

Kevin

Itasca Inboard


Hi Kevin,

I have a 1986 Itasca motorhome in which I have installed a 2001 Chevrolet 8100 Vortec Mag HO Engine from a Mercury inboard set up.

My problem is with the wiring loom and the fact that the plugs appear to be wrong. As the loom is from a truck I thought that a marine electrical loom may be more suitable. The loom would be stand alone – engine only – but with a fly by wire throttle pedal.

Do you have any ideas as to how to make this work?itasca-motorhome

Francis

Hi Francis,

Sounds like a fun project.

The inboard engine should have all of the electronics required to run mounted directly to it. The only wires needed to get it to run would be 12 volt power from a key switch (usually purple on the engine wiring) and a momentary start wire from the key switch (usually yellow/red). Coming from the engine, the gray is the tachometer lead, the light blue is the oil pressure, and the tan is the water temperature.

I don’t have experience with fly by wire throttle. Most of the Merc engines in that era were a straight cable to the accelerator. Good luck with that part.

If you can find it, ebasicpower has a ton of short engine harnesses and boat wiring harnesses that may make your adaptor magic easier to accomplish.

Good luck,

Kevin

Wiring a Boat’s Carbon Monoxide Detector


Hi Kevin,

Could you please briefly outline location of carbon monoxide detector on a cruiser? Do I have to dedicate a unique circuit to the monitor.

My boat has two state rooms so I assume two monitors are required. My current plan is to wire directly to bus bar coming off battery and not to main electrical panel.

Thanks,carbon monoxide warning

Sanford

Hi Sanford

I would refer to the CO monitor’s installation manual or the manufacturer’s website for the best location.

  • Size the wire for 3 percent voltage drop but do not use wire smaller than 16 awg.
  • Use circuit protection at the source of power.
  • If you are using a breaker, I like to use a push to reset style for co monitors instead of a rocker style to make it more difficult to turn off.

I also prefer to wire CO monitors and bilge pumps to have constant power and not be controlled through a battery switch, but sometimes it is not possible to accomplish this.

Hope this helps,
Kevin