Internal Regulated Alternator Conversion

[clemsonfor]

IMPORTANT UPDATE

OK, so just got of the phone with Ken (kenmac) and we learned something new and important about the IR Alternator Conversion:

Your OEM Yanmar 'charge warning light' bulb must be good for the Internal Regulated Alternator to charge.

Ken's charge light bulb was blown and the alternator would not produce a charge when started (brief slight panic on my end for obvious reasons having posted this thread). But once we figured out his bulb never came on at any key position, and he swapped in a good bulb from his oil light, all worked as it should, ~14.2 volts alternator output with his new battery that had been used for a few quick start-stops (whew! sigh of huge relief on my end, and his too).

Once the engine is started, he can pull the bulb and the IR Alternator stays at full output, but if started without the bulb it won't - so apparently that bulb in series in the circuit plays some function similar to 'exciting' the IR Alternator on start-up, after which all is good. The bulb still works like OEM - it's "ON" with key-on-engine-off, and "OFF" with key-on-engine-on and the alternator generating output (correct warning light function).

I never tested mine with that bulb blown or removed so didn't know the critical role that 'idiot light' plays in the system with the IR Alternator. So, if he/I/anyone with this IR Alternator Conversion ever note our charge light does not come on with key-on-engine-off we now know to check that bulb to ensure our battery will be charged when the engine is running.

In the end, Ken now has perhaps the 'second in the world' Yanmar with the Internal Regulated Alternator Conversion and it seems to work as I promised. Gotta thank Ken for his patience and perseverance and for boldly stepping-up to give it a try - hopefully he'll enjoy another 30 years of trouble-free operation with the new system.

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Also we note that ordering the same PN I ordered from RockAuto, the alternator Ken received was a Mitsubishi brand rebuild by AC Delco (mine was a Hitachi brand). Though the Mitsubishi has an unused mystery extra terminal on the back it's apparently an equivalent alternator. Physically it bolted-up no problem, the pulley matches exactly, etc, etc.

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Final aside - in the process of our long-distance trouble-shooting and visiting Ken and I realized that a relative of his is a long-time acquaintance of mine. Small world for sure, gotta love the coincidences of new TBN Forum friendships.

Good info!!

And that's crazy that you know the same people!! Small world for sure.

 

[kenmac]

I just want to say BIG THANK you to Alan. He is one smart cookie, an asset to me and this site.
I couldn't have accomplished this task without his willingness to assist me. And for that, I'm very grateful !

Wish we lived closer instead of a what seems like a world away.

 

[vmaxman]

I've got an old Kalmar forklift with a Nissan engine here @ work.
The alternator is shooting sparks out of it and the voltage regular pins are all corroded. ONe to the point of total disappearance.
The fork lift shop wants $160.00 for a direct fit alternator. I didn't ask about a voltage regulator.
My wiring colors are a bit off from what is listed here. We will trace them out and then install the AC Delco 334157 unit. I ordered it from Napa since we have an account threre.

Thanks for the info here. I'll let you know how it works out.

 

[vmaxman]

I've got an old Kalmar forklift with a Nissan engine here @ work.
The alternator is shooting sparks out of it and the voltage regular pins are all corroded. ONe to the point of total disappearance.
The fork lift shop wants $160.00 for a direct fit alternator. I didn't ask about a voltage regulator.
My wiring colors are a bit off from what is listed here. We will trace them out and then install the AC Delco 334157 unit. I ordered it from Napa since we have an account threre.

Thanks for the info here. I'll let you know how it works out.

Finally got around to this today.
As noted previously, our wire colors were different in the connector to the regulator. After testing them, we found the pin out to be the same.

Everything works good now.

 

[rdgemmill]

This not for everyone, maybe of interest if you need to replace your voltage regulator, alternator, acquire a tractor with major wiring kludges, or just like simplified electrics.

This all in the context of a 336D but some (many?) other Yanmar models are identical or very similar - up to you to determine similarities or differences and adapt as required for your specific situation. I have done this mod on my Yanmar and it works perfectly. Even if doing this on a 336D it's up to you to verify everything matches your tractor.

Background

• The 336D shares the 35 Amp alternator and external mechanical voltage regulator found in several '60s and '70s Datsun/Nissan cars/small pickups.
• Datsun/Nissan later went to an internally regulated (IR) alternator of identical capacity, yielding simplified wiring and more reliable operation (the IR alternator uses a solid-state regulator system)
• The Datsun 1200 Club Forum has popularized and fully documented the upgrade from the older alternator+mechanical regulator system to the more modern IR Alternator system
• This post builds on that information and documents my implementation on the Yanmar 336D application

Cost and Fitment

• As of this date the price of the Hitachi LR-135 IR Alternator I used is $47.79 including the core charge but not including shipping from RockAuto (note too that 5% off codes for RockAuto are widely available via internet search)
• That price is competitive if not better than many of the Yanmar voltage regulator only replacements or alternator only replacements, while serving to replace both the alternator and the voltage regulator
• That's for a Hitachi alternator remanufactured by AC Delco and shipped in AC Delco packaging with 24-month warranty
• The alternator is complete with pulley and for me was an exact physical match bolt-on with zero modification required to any of my Yanmar mounting brackets / adjuster; the threaded adjuster-bolt hole in the alternator casting was exactly as OEM Yanmar
• See this link for the RockAuto detail page including dimensional data to verify mounting fitment for your situation RockAuto ACDELCO 3341571 = Hitachi LR-135
• In addition to the alternator, the mod requires a few inches of wire and 4 standard crimp-on male 1/4" blade connectors (to DIY two 'jumpers' installed at the OEM Yanmar 6-blade voltage regulator harness connector upon removal of the OEM regulator)
• Yes, the OEM Yanmar 336D 'charging warning lamp' will continue to function exactly as original.

Instructions
See and study the attached Figures 1 through 4 .... post-up if you've any questions.

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I have tried this modification on my Japanese built Ford 1910 which has virtually the exact wiring. I am getting around 15.85 VDC while charging and the battery light seems to stay illuminated. I do see two differences in that my bulb is a 3 watt and the fuse for the lamp circuit is 15 amps. Do you have any ideas of what I might try to get the voltage down to the 14.5v range?

Thanks,

RDG

 

[kenmac]

he hasn't posted since 2018.. I hope he's doing well. He was a huge help to me

 

[California]

...getting around 15.85 VDC ... Do you have any ideas of what I might try to get the voltage down to the 14.5v range?

Does anybody know: would a rectifier in series with the alternator output be a suitable way to drop this voltage?

 

[radios1]

Does anybody know: would a rectifier in series with the alternator output be a suitable way to drop this voltage?

yes, but you would need 2, since each would drop .7 volts.. it would have to be able to handle the full output of the alternator also!..

 

[Chillman88]

I have tried this modification on my Japanese built Ford 1910 which has virtually the exact wiring. I am getting around 15.85 VDC while charging and the battery light seems to stay illuminated. I do see two differences in that my bulb is a 3 watt and the fuse for the lamp circuit is 15 amps. Do you have any ideas of what I might try to get the voltage down to the 14.5v range?

Thanks,

RDG

For what it's worth, I did this on my 1910 last week and it's charging correctly. It's reading 14.8v but I'm pretty certain my voltmeter is reading slightly high anyway.

I just wanted to post this in case someone else finds this thread and is curious about it just like I was.

The alternator I was sent has a spade connector for the ground terminal instead of a stud, other than that everything works properly including the indicator light. Even the regulator plug has the same pinout as the writeup.

I'm guessing the quoted post either has a bad regulator, or voltage drop over the voltage sense wire which goes back to the ignition switch on this particular tractor.

 

[pmsmechanic]

I was hoping this would work as an upgrade on my 4410. No such luck as I need a wire to send a signal to the tachometer.

Just an explanation on how the charge light works. The light is fed positive off of the key. The other wire goes to the alternator. When the alternator is not charging that wire is connected to the negative side of the electrical circuit. As the alternator starts to charge that same wire starts to put out a positive voltage. 2 positives at the light bulb turns off the bulb.

The alternator needs to sense a positive voltage from the key through the light bulb in order to start charging. That's why it won't charge if the bulb is burnt out.