331 Oceanis wiring diagram

Apr 19, 2021
5
beneteau Oceanis 331 Collins Bay, Lake Huron,
Has anyone laid his/her hands on a real wiring diagram for 2001 Bene 331 Oceanis made in NC for North American market (i.e. 120V AC)?
But I am really after the 12V system diagram. Trying to find out what devise has been used for starting and house batteries separation and where is it located.
Thanks
 
Nov 21, 2007
631
Beneteau Oceanis 34 Kingston, WA
You should have two red battery on/off switches for the positive side of each battery, you can turn each battery on or off independently. On my system, the engine battery is not joined in with (or in place of) the house battery. But, I have heard that that has not always been the case.

[edit: …”has not always”…]
 
Last edited:
Apr 19, 2021
5
beneteau Oceanis 331 Collins Bay, Lake Huron,
Thanks SoSound. When I cruise, I keep all my batteries ON and on anchor, in the morning, my house batteries are below 12V while my start battery is always above 12V. So it implies, that they are separated by an automated charging relay (ACR) or a system of diodes. I plan to put a new charging system (the existing original is ineffective) and plan to charge my house bank with a new, high output alternator. If there is an existing ACR I can reuse it, but with the diodes, perhaps not. The wiring diagram /schematic in the boat manual is a joke/cartoon type sketch. Internet search did not reveal any. Need help of my fellow boaters. BTW, I love my this spring acquired Bene 331. But not the charging system or manual.
 
Nov 21, 2007
631
Beneteau Oceanis 34 Kingston, WA
I doubt that there is any automated charging system in a “standard” 2001 Beneteau. I think it’s more likely a separate wiring harness for the engine and related systems, and the house systems. As far as I know, my 2014 is still old fashioned memory (remember to turn it off) and separate switches. Yes, the wiring diagram for your era boat would be pretty sketchy (pun intended), but my 1990 Beneteau and my 2014 Beneteau had very similar basic wiring setups for connecting the batteries. Some of the newer boats have had decent wiring diagrams in the owners manual, but I’m currently stuck working from my iPad and don’t have access to my PDF version of the manual.

Hopefully, some of the other active Beneteau owners will contribute both specific knowledge of your era electrical system, and some diagrams which make sense. They’re also probably more knowledge and technically qualified than I am.

FYI, I added two 110 W flexible solar panels to my charging system last year, and it’s made a huge difference. During the period that would be the Great Lakes cruising season, I don’t worry at all about my house batteries, even with a refrigerator and a forced air heater.
 
Jul 23, 2009
857
Beneteau 31 Oceanis Grand Lake, Oklahoma
The 12 volt systems in my 88 First 285 and my 08 Oceanis 31 are quite different.

Both batteries on the 285 were wired through independent switches but to the same buss. The buss on the 285 served the starter and the house loads.

My 31 has two house batteries wired to one switch and one start battery wired to a separate switch. The alternator is wired through a transistor type isolator. The current/original alternator is very week but I don't really need more yet. The previous owner didn't even know there was a start battery.
 
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arf145

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Nov 4, 2010
484
Beneteau 331 Deale, MD
My French made 331 did not come with any devices to separate batteries--beyond switches. I've since rewired things so that the house bank handles everything and is always charged, with the backup battery getting it's charge from an Echo Charger.
 
Apr 19, 2021
5
beneteau Oceanis 331 Collins Bay, Lake Huron,
Big thanks, my fellow Bene owners.
It's kind of pathetic of Beneteau not to provide wiring diagram in a manual. Over time I will trace the major wires and make my own.
Interesting that SoSound has a huge difference running two 110W solars. Mine of 150W with a small wind is next to useless delivering up to 6 amps in mid day and the fan makes some noise mostly with about 1 amp below 10 knots wind. If it is not for a Honda 2000 generator we would have wrecked the batteries for sure when out on Georgian Bay for 4 days.
 
Nov 21, 2007
631
Beneteau Oceanis 34 Kingston, WA
Interesting that SoSound has a huge difference running two 110W solars.
Just to be clear, I installed two 110W solar panels, and discovered that two group 31 batteries would fit in the boxes that housed the standard group 27 batteries that were original equipment.
 
Apr 19, 2021
5
beneteau Oceanis 331 Collins Bay, Lake Huron,
Thanks Bluenose,
Great help. I was actually planning similar redo, but the negative switch new function is a good idea. I wonder if it reasonably easy to access the wiring. Did you upgrade the alternator as well?
 
Apr 19, 2021
5
beneteau Oceanis 331 Collins Bay, Lake Huron,
Thanks Bluenose,
I am just about to call Balmar and order a new 120A alternator and serpentine conversion kit. Regretfully, I found the existing 50A alternator quite useless. Over about four days away from shore power, we were motoring perhaps 50% of the time and by evening I had to run my little Honda 2000 to stay above 12V. I am planning to attack it from all angles by adding solar panels, batteries, and new alternator with redone charging system. Thanks to this forum I just found out that the start and house batteries have no idiot-proof separation, so we were lucky to be able to start the engine.

I am really grateful for all the info.
Wish I could buy you all a beer one day.
 
Jan 10, 2018
260
Beneteau 331 Halifax
Me too! Look, I would think about a new alternator. I don't think you need one. I think you should measure twice and cut once. If you are having these issues, get someone highly recommended and qualified to look your system over first before you spend $$$'s on a new alternator. It sounds to me like there are other issues that need addressing. I would have everything checked out first.
 
Mar 20, 2016
594
Beneteau 351 WYC Whitby
Thanks Bluenose,
I am just about to call Balmar and order a new 120A alternator and serpentine conversion kit. Regretfully, I found the existing 50A alternator quite useless. Over about four days away from shore power, we were motoring perhaps 50% of the time and by evening I had to run my little Honda 2000 to stay above 12V. I am planning to attack it from all angles by adding solar panels, batteries, and new alternator with redone charging system. Thanks to this forum I just found out that the start and house batteries have no idiot-proof separation, so we were lucky to be able to start the engine.

I am really grateful for all the info.
Wish I could buy you all a beer one day.
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