Converting to GM Alternator

Mark777

Member
Hey Folks,

I found the contents of this thread very useful. If anyone has a generator, magneto, current limiter/voltage regulator set up...then you probably understand why this type of upgrade is such an improvement over the stock factory set up.
The smaller Yanmar diesel tractors (and all other smaller Asian tractors) that are equipped as stated above, at best, are just adequate to supply the basic output to keep ones battery fully charged....and that's all.

Optional 12V electrical equipment like work lights, road flashers, radio and even a power inverter will prove too much for the stock charging system. The following pictures show what one person did to upgrade his very small GT14 Yanmar. I did ask his permission, and he said "use anything that might be helpful for someone contemplating a permanent fix" He used the ever popular internally regulated GM alternator which can be found at any auto parts store.

1) First and second picture-A very tight and confined area.
2) Third and fourth pictures of hand made/altered brackets.
 

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Mark777

Member
The last few pictures show the completed installation and the simple wiring diagram....

The GM 3 wire diagram prices run anywhere from $50. for a rebuilt to $300. with an output of 60 amps to the $300. (200+ amp) fit should you need power for your ambulance!!

Hope you enjoy,

Mark
 

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Mith

Active member
Mark, thanks for posting.
Thats a very clean install.
Looks like it would be possible to do a very similar install on Yanmar CUTs, and probably on other brands too.

I dont know why manufacturers dont install better alternators from the factory, they seem to be pretty marginal for the stock use, and alot of users seem to add lights etc.
 

Mark777

Member
No problem Jim...and surely this application would be for any gasoline or diesel powered equipment should one want to operate 12V ancillary options.

The price of one voltage regulator, new, from a Yanmar supplier is more than the price of an internally regulated 10S 3 wire, GM alternator. Another plus is using the existing stock charge lamp on the dash panel.

Oops...looks like I duplicated one of the pictures :(.

Mark
 

Grrrr

Member
I dont know why manufacturers dont install better alternators from the factory, they seem to be pretty marginal for the stock use, and alot of users seem to add lights etc.

I expect it is a cost thing and manufacturers think that they can get away with it without consumers noticing.
 

HeyBob

Member
I expect it is a cost thing and manufacturers think that they can get away with it without consumers noticing.


Manufacturers want their replacement parts cost high, especially in my industry, it makes new equipment look very attractive. Replace rather than repair.
 

Mith

Active member
Mark, I tried to install an alternator off a car to my tractor last year, but I think the one I used needed a voltage applied to it before it would start to generate power.
One day I must get my head around it and try to make it work again.
I'd assume the one used in the photos starts generating when it is rotated straight off the bat, or does the connector marked 'to the fuse block' provide power to the alternator?

Bob, I think Jake was referring to using a marginal alternator as a cost cutting method to lower the price of a new unit, rather than increase the price of parts.
In the garden machinery trade it seems manufacturers try to keep the price of parts competitive, particularly wear items. Honda seem to keep the price of parts very high, and I at least wont buy a Honda for that reason.
 

ghautz

Member
That is a neat conversion. I have thought about doing something similar to my YM1500D. There is not room for an alternator that large, however. I wonder if something smaller is available. I don't need that much power capability, anyway. What is used on small ATVs, etc?
 

Mark777

Member
......Mark, I tried to install an alternator off a car to my tractor last year, but I think the one I used needed a voltage applied to it before it would start to generate power.

I'd assume the one used in the photos starts generating when it is rotated straight off the bat, or does the connector marked 'to the fuse block' provide power to the alternator?..........


Pretty sure the wire marked 'fuse bank' goes from there to the ignition switch. Once the key is in the ON position, the alternator (and internal regulator) are HOT. No recuperative power to the battery will be realized until the engine is running and the alternator is spinning.

ghautz, It's a win win deal in my opinion. His alternator was shopped by SIZE*, ease of installation and durability.

*The actual dimensions of his alternator per DB Electrical web site (www.db-starter-alternator.com) is:

Diameter - 4"
Length - 4 1/2"
Mounting holes center to center - 5 3/8"
Weight - 5.5 pounds
Output - 60 AMPS

NOW THAT'S TINY!!. I've already measured my YM1401D and there is room to spare....I'd bet there would be no problem converting your YM1500D.

DB Electrical also has an excellent "Alternator Tech Tips" section that is a very good read.

Mark
 

ghautz

Member
NOW THAT'S TINY!!. I've already measured my YM1401D and there is room to spare....I'd bet there would be no problem converting your YM1500D.

Mark

I looked more closely and figure it can be probably be done. It would require rerouting the wiring harness and possibly finding a way to reinforce the radiator support. It would also require removing the lower radiator hose and radiator drain whenever the v-belt needed replacing. Those restraints are not unacceptable. I figured, that given I don't need all the power capability of that alternator, that there might be something small enough to fit where the present alternator sits.
 

Mark777

Member
I would love to do the conversion when it needs to happen. I don't think I'd hesitate the changeover.

I'd also like to hear from someone that's done this recently, as I haven't heard back from the original poster, and how the performance enhancements have benefited him.
 

California

Super Moderator
Staff member
Site Supporter
I wonder how many owners actually need 60 or 200 amps.

Some people run an electric winch or snowplow lift, or have a big inverter to drive a hedge trimmer or something. But I wonder how many amps those applications really require.

I thought 200 amp alternator upgrades were only used for boom cars. :D
 

Mark777

Member
Yeah California....I'm thinking I might not ever use the additional output these new alternators provide. What appeals to me most is the GM internally regulated alternators are available just about everywhere, very durable, they eliminate (2) voltage regulators (primary current limiter and secondary dash lamp VR.) which replacement costs are $86.08 and $35.24 respectively, and should the main generator (magneto) fail, (and they seldom do) tack on another $131.83.

IMHO, the complete replacement costs to overhaul the original charging system will be over $250 with shipping and still have no additional benefits that the GM 60 AMP change over provides (and at less than half the costs for the new alternator, wiring and belt).

The much larger 200 plus AMP alternators are designed for emergency response vehicles, motor homes, campers and marine applications...or many vehicles with deep cycle, back up batteries and high output power inverters.
 

toolegit

New member
Voltage regulator

I know this thread is pretty old but it's worth a shot. I have a Yanmar 146 and I keep blowing Voltage regulators. I'm not sure why it's doing this, double checked grounds and havent seen any other obvious reason it's blowing them. With this conversion I understand it replaces the voltage regulator but I'm not sure what you do with the wires that went into the voltage regulator. I see that you run a wire from the alternator to the battery and then one off the side of the alternator to the ignition switch or tap the wire, but where do the other wires go? There's a total of 6 wires going to the vottage regulator. Where is this secondary dash light voltage regulator? behind the dash? do I disconnect it after the conversion or reroute the wires somewhere? Any help would be appreciated I need to get this fixed asap. Thanks!
 

gt14

New member
I did this conversion and its still charging nicely after more than 10 years.

I originally posted this on tractorbynet.com I am glad others are using my efforts to improve their tractors as well. Yanmars are great tractors.
 

gt14

New member
You don't use the other wires that go to the regulator. One wire goes directly to battery. The other goes to the fuse that comes from ignition switch I can take pics of my wires if you want. In the wiring schemo the regulator has 6 wires B L L R and G and unmarked in book.
G goes to charging indicator light.
the other goes to 5 AMP fuse
B feeds all your circuits
L and L go to alternator.
R goes to battery

The regulator just limits the charge so it doesn't put too many volts into the battery. The alternator does the automatically.
 
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