Upgrading stock 60A alternator to Balmar 60 series 100A on Yanmar 3YM30

[ToddS]

Last summer my big question was "Do I need a new alternator"... and to make a long story short, the answer was yes (and you need other things too). @Maine Sail and others were helpful in answering that question (that backstory is here: Do I need a new Alternator?).
In the fall, I got a very good price on a new Balmar 100A alternator (and regulator, and sensors, etc.) and now I'm installing it (on the hard). Knowing the original owner, I'm fairly certain everything electrical on the boat (Beneteau 373) is exactly as it was delivered from Beneteau. I'm admittedly more mechanically inclined, than electrically (though I'm learning), and the install of a new alternator obviously requires a bit of each. Anyhow, in detaching the stock alternator, I found that the + post had two wires attached, the heavier one going to the starter and a small one going to a relay. Similarly, the - post had two black wires, the smaller one going to the same relay, and the larger one disappears into a difficult-to-follow harness with lots of other wiring, but that's fine, I know that's working, and is an obvious swap onto the new alternator. I THINK the relay box wiring is there to ensure the windlass is only used while the engine is on... not certain, but I'm not terribly worried about that right now either. I can figure that out.
What I'm not 100% sure about are the other wires.

• stock alternator has a sort, white wire on the back that is connected to an orange wire which disappears into the previously mentioned harness, which has bundles inside bundles, inside bundles, and I'd rather not disassemble, but I have a hunch that orange wire is the tachometer... (but I'd like to be more sure than a "hunch")
• a "tee" shaped socket on the back of the alternator with two blade-shaped connections in it, has two reds and one blue wire coming off it, all going into the previously-mentioned bundle/harness which snakes around the engine in places my hands can't fit.
• BONUS: as I removed the alternator, I found a small, white wire coming off out of the harness with the other wires, with a blade-fitting at the end, It is possible that it "fell" off as I was disconnecting the stock alternator, but I can't find any corresponding connection on the alternator where it could have come from. Either I'm missing something, or maybe it was just sitting there unused for years, and I'm just noticing it now as I can finally see into that space.

I'm assuming that someone with the same engine and/or boat will have accounted for the various wires in this original setup. Can anyone advise on whether that orange wire is the tach? Where do the red and blue wires in that "tee-shaped" connector go? What my mystery white wire might be? I sure wish I could just follow the wires to see where they all go, but would really also like to avoid major surgery, as the harness seems to join/split several times in places I can't fit my hands. Thanks.

 

[JohnShannon]

Have you tried googling the Yanmar wiring diagram? It might all be explained there.

 

[Stu Jackson]

a new Balmar 100A alternator (and regulator, and sensors, etc.)

Does this mean you bought an external regulator?

a "tee" shaped socket on the back of the alternator with two blade-shaped connections in it, has two reds and one blue wire coming off it, all going into the previously-mentioned bundle/harness which snakes around the engine in places my hands can't fit.

You need to make a wiring diagram BEFORE you go connecting wires. Like this:
Alternator Regulator Wiring Diagrams - all three Alternator Regulator Wiring Diagrams (all three)

I sure wish I could just follow the wires to see where they all go, but would really also like to avoid major surgery, as the harness seems to join/split several times in places I can't fit my hands.

You may not be able to avoid it. But if you start with a wiring diagram, you may be able to "deduce" where they SHOULD go and look there to see if that's where they end up.

You should also be aware of this info from Maine Sail:
Beneteau Wiring Diagrams - Maine Sail's corrections - Just in case you have a friend with a Beneteau and want to help him with his OEM wiring Reply #8
One black and two red electrical switches

If you would like to learn more about alternators, try this attached file.

 

[ToddS]

@Stu Jackson
Thanks.
Yes, I bought external regulator.
and Yes, I've seen @Maine Sail 's take on the standard Beneteau wiring. I agree with some of it... fuses for example... but some of it is to make the switches more intuitive, and I find the way the shutoff switches are wired to be perfectly intuitive. Any batteries that are are turned on are being used/drained, and any batteries that are turned off are not. Shame on someone who leaves a battery "on" and assumes it isn't being drained (IMHO). Anyhow, the way it is works fine for me, so I have no plans to change that.

As for a wiring diagram... The whole reason I'm writing is to see if anyone has hints as to where any of those wires go so that I can complete my diagram... none have been touched since leaving the factory, so I figured with a fairly common manufacturer, boat, and engine, someone might save me the hassle of unbundling everything in places I literally cannot reach with human arms... any suggestions, I would take with a grain of salt and test out, but other than the main red+ and black-, the rest aren't obvious to me. I would literally need to take off the starter motor, and heat exchanger just to be able to reach some of the wiring connections in there, as well as pull apart layer upon layer of tape and conduit just to see what is what.

If nobody knows this information, I'll obviously be stuck doing the legwork entirely from scratch on my own... but figured this would be a good place to start looking for advice. It's not some obscure boat, or something the previous owner wired up himself. It's literally one of the most prolific boat manufacturers (if not THE most) with a stock Yanmar engine with original alternator, and original wiring. I only wish Beneteau or Yanmar had diagramed any of this... surprising I can't find documentation on that either beyond the over-simplified stuff from the manufacturer like this: http://sailingpearl.com/wordpress/wp-content/uploads/2011/11/373-owners-manual-R02-hull-22-up.pdf

 

[Maine Sail]

Todd,

Your Balmar dealer should be helping you with this.

These may help:

https://marinehowto.com/category/alternators/

 

[Bob S]

Todd,
What engine do you have. I found a Yanmar service manual on line and it's not the best for legibility but it should give you an idea. See chapter 9.

 

[ToddS]

@Maine Sail - I had read your (helpful) documentation, though it didn't specifically answer my questions... your suggestion to contact Balmar is a good one, and I'll likely try them tomorrow.

@ Bob S and @JohnShannon - Interesting - The first thing I did, even before posting anything here was read MY Service Manual (for my Yanmar 3YM30), but you pointed me to a different Service Manual for a different (though similar) engine, and the one you (@Bob S ) pointed to has WAY more electrical system detail than the one for my engine. Its like they left out a whole section from the 3YM30 manual that's included in that one. Even though it is not exactly the same, I looked and got a few hints from that doc so thanks for that lead! I actually saved a copy of that doc as well, even though it's not my engine, several components ARE identical and documented there, and not documented in my own engine's manual. I didn't even think to look for documentation on OTHER similar engines.

 

[NYSail]

Didn’t read your whole post but my boat had same relay..... it’s for the windlass which only runs when engine is on. I left it for the time. I upgraded my alt with a 150 amp Balmar I got from main sail...... best price and fabulous after purchase support during my install!

good luck!
Greg

 

[NYSail]

Also beneteau loves to harness large groups of wires..... I tend to cut them open to follow things when needed. I cut the engine harness open when changing my alt. Also beneteau loves to strap hoses to the wire harnesses behind walls so it makes changing hoses real fun......
Anyway try going to your engine panel in your cock pit. Go behind and observe what wires from the harness go where. Take a bunch of pictures / videos.
Good luck!

 

[Maine Sail]

While Balmar can help, the dealer you bought this from should really be the one helping.

The wiring process is simple.

1- Wire alt direct to house bank (consider and alternator service disconnect and size this wire for no more than 3% drop)
2- Use engine schematic to locate wire in stock alt T-Plug that will be used for MC-614 ignition feed (reg brown).
3- Remove the 10GA red wire from the stock alt harness that goes from alt B+ to starter motor
4- Wire voltage sensing correctly
6- Program the regulator and don't forget belt load manager
7- Install battery and alternator temp sensors.
8- Hot load test the alternator (using a 100A + dummy load) and ensure it does not exceed temp limit.

 

[ToddS]

I installed the alternator (with belt-buddy) and regulator. And figured I'd update any curious minds as to what I did. It MOSTLY follows the advice from @Mainsail, as well as advice I got from Dale at Balmar. There are a few choices I made (for now) that seem okay to me, but that could always be improved/upgraded further in the future as well.

• Replaced stock alt with new Balmar 100a dual-foot alternator and installed external regulator.
• Adjusted, shimmed, etc. new alternator to ensure good wrap, longer belt, proper alignment, tension, etc. etc.
• Balmar Alt D+ goes to Yanmar harness blue (charge light)
• Balmar Alt blue goes to ARS-5 regulator blue
• ARS-5 harness red and black go to the house battery + and -
• ARS-5 brown goes to Yanmar harness red w/ black stripe (ignition wire)
• White on Balmar Alt goes to ARS-5 terminal #7
• Orange from Yanmar harness goes to ARS-5 terminal #8
• Alt temperature sensor wire between regulator and alternator
• Battery temperature sensor wire between regulator and "middle-most" post in house battery bank
• Instead of main red/black going to starter as Yanmar had wired it, I wired them to my Beneteau battery switches which are very close-by. I KNOW that @mainesail's advice is to go directly to the batteries (and he's not wrong), but instead of a longer run to the batteries, I used heavy (2ga) wire to go a short distance (2 feet) to the switches (yes, that's an extra connection with some cost/loss) where they connect to #2/0 wires that go to the battery bank.

Personally, I find the 2 red switches that Beneteau uses intuitive (I know MANY people don't), and I don't mind at all how they work. Any battery/bank that is switched OFF is disconnected from everything. Any battery/bank that is switched ON is connected to everything. My procedure is that when I'm using the boat for non-engine-related things, I turn on the house bank. When I'm starting the engine, I turn on the engine bank (house is generally already on at that point). When I'm turning off the engine, I turn off the engine bank. Works for me.
In theory, I could be dumb enough to turn off the batteries while the alternator is running, and that would be very very bad for the alternator. That being said, in 20 years of sailing, I've never once done that, or been tempted to... so that's very unlikely. I COULD have wired the alternator to the battery side of the switches or to the batteries themselves, to keep them always connected... and then wired a service disconnect (as @mainesail advises), but I think FOR ME, it is way more likely that I would accidentally forget to use the service disconnect switch, (leaving wires hot where I was working), than accidentally turning the battery switches OFF while the engine is running.
I changed just a few settings on the regulator... though I may read up and adjust more... but TO START WITH, the only settings I changed are:

• Battery Type to match my battery type (AGM)
• Bulk Voltage raised to 14.5 (per battery manufacturer's recommendation)
• Float Voltage raised to 13.5 (per battery manufacturer's recommendation)
• Belt manager to 80% for now... I may adjust further as needed over the summer as I keep an eye on belt-dusting, alternator temperature, and how well the 80% setting meets my charging needs, etc.

It's all new, so I can't speak much to the results, but I ran the engine 2 or 3 times, both in neutral and under load, at various RPMs ranging from 1000 to 3000 for a total of about 2 hours, and so far everything seems great... way better output than before... nothing was getting too hot... tachometer works... no errors... no strange noises or smells, or dust, though of course I know it's early still and I'll be closely monitoring it all. Oh, and I rerouted the factory blower fan input/output ducts to better cool the new alternator... and that fan runs whenever the ignition is switched on.