Alternator conversion kit.

I am wondering where I can get the best kit to convert my mag type M to 12 volts. I would like to do not cuttting to the hood as well as one that kicks in and charges at low engine RPM. Also would like a complete kit with instructions.
Any ideas on which kit is best in each of your opinion would be very much appreciated.

You already have all you need to convert your M to 12v. Just take the generator to a good auto electric repair shop & have it stepped up to 12v. Can even have it changed over to neg. ground if you want. You'll spend less than what you would spend purchasing a 12v alternator.

I've had two done. First one the guy didn't charge me anything for it. 2nd one cost me $35, but it had to put some new parts in it, Probably didn't take him 5 minutes to do the first one.

There are hundreds of pictures and comments on this topic. Most of the Kits (from this site and others) are one wire setups. This is OK, but many have had battery drain issues if left for a week or two. (the alternator in the one wire setup continues to sense battery voltage, and thus draw some current. (some conversion alternators are very low consumption, and not an issue, others draw enough to be a noticeable issue. I do not know which manufacturers make the good ones, so I cannot comment.
I believe the easiest solution is to use a Hitachi alternator from a 85 Nissan truck (721 truck) This alternator is smaller in diameter and well suited to the task. It is wired easily.
it has three connections. one goes to the amp gauge (fat #10 wire) it is the big output post.
There is one labeled S it attaches directly to the big post going to the amp gauge.
The last connection goes to a 12v source that is on when the tractor is running. In the case of a mag like yours, a wire is run from the amp gauge (same place as the alternator output wire) to an oil pressure sensor switch from NAPA (it is off when no pressure, and on when pressure is in the system. This sensor is "Teed" into the oil gallery (where the oil pressure gauge is located is fine) From the second terminal a wire extends to the L terminal of the Hitachi alternator.

The alternator is v belt driven, it is small. it can use the original gen mount with a little spacing, and they are cheap.

Be sure to change the light bulbs and all is well. Jim

It is not a matter of manufacturer that makes the difference but rather what the regulator was designed to do. It is mostly a matter of whether you are going to have low cut in speed or low parasitic draw.

The draw through the regulator is used to provide a small voltage through the brush and slip ring to the field coil in the rotor to provide enough magnetic lines of force to get the alternator to start charging. The lower the magnetic field the higher the RPMs need to be to generate enough voltage to start charging. The higher the voltage the more milliamps it draws but it also lowers the RPMs needed to get the alternator to start charging. Once the voltage produced by the stator exceeds the voltage that the regulator is providing to the rotor coil, the voltage in the rotor rises and in turn increases the output from the stator. It keeps increasing until the regulator takes over to control the output voltage.

The output from the diode trio is connected though the regulator to the number 1 terminal. That allows regulated voltage to be applied to the field coil instead of the just the small amount the the regulator passes though with the alternator at rest. That is why once the alternator starts to charge the RPMs can go quite low and the it will continue to charge.

Charging voltage is controlled by the regulator by grounding the other end of the field coil as it returns through the other brush and slip ring. When grounding the regulator tab through the D shaped hole in the back of the case you all taking the regulator out of the circuit and causing maximum current flow through the field coil in the rotor.

Voltage sensing to serve as a voltage control is usually done at the number 2 terminal but there are some regulators that have no connection at that terminal and use either the voltage provided by the diode trio or separate wire coming from the rectifier bridge. Those that use a separate wire will have a small stud to attach the added wire.

Converting the generator to 12 Volts does not solve the problem of an expensive, unreliable, complicated generator/regulator setup.

As far as kits, the only kit I have experience with is Jensales' so-called "kit" which consisted of a $35 one-wire alternator and a photocopied sheet of so-called "instructions." Total cost? Around $150.

There were no brackets. We had to make our own bracket.

There was no wiring harness. We had to rewire the tractor, figuring it out along the way.

If you are at all mechanical, I would recommend that you skip the kit and get yourself the cheapest rebuilt Delco 10SI alternator they have at your local auto parts store. You'll save yourself a LOT of money.

(quoted from post at 08:03:45 06/03/10) Converting the generator to 12 Volts does not solve the problem of an expensive, unreliable, complicated generator/regulator setup.

As far as kits, the only kit I have experience with is Jensales' so-called "kit" which consisted of a $35 one-wire alternator and a photocopied sheet of so-called "instructions." Total cost? Around $150.

There were no brackets. We had to make our own bracket.

There was no wiring harness. We had to rewire the tractor, figuring it out along the way.

If you are at all mechanical, I would recommend that you skip the kit and get yourself the cheapest rebuilt Delco 10SI alternator they have at your local auto parts store. You'll save yourself a LOT of money.

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Well said. I've done two. I put the Hitachi on my 140 and a 10SI into a 1955 Ford pickup. All the kits I saw were rip-offs. Skip the one-wires and go with a light or diode. I used an e-bay bracket on the Ford and spacers on the 140. You will get better instructions off a site like this (or yblock.com for a Ford p/u) than come with the kit.

Hi there! new guy here... I'm looking for an Alternator Repair & Conversion Kit... Anyone here has a recommendation on what's the best to have? I searched about this SMP brand but I'm not sure if it will be a right choice... Any help is very much appreciated.. Thanks!

Next time, instead of hijacking a year-old thread, hit the button that says "NEW TOPIC" at the top of the screen.

What do you mean by, "alternator repair & conversion kit?"

You can get alternator REBUILD kits at your local auto parts store. All you need to know is the model of your alternator.

What are you converting the alternator into? Do you mean a kit to convert a tractor to 12V with an alternator?

There are no kits out there that are worth the money. All you need is the cheapest Delco alternator your local auto parts store sells, a piece of threaded rod, a couple of nuts, and some wire. Total cost about $60.

(quoted from post at 20:33:18 04/28/11) Hi there! new guy here... I'm looking for an Alternator Repair & Conversion Kit... Anyone here has a recommendation on what's the best to have? I searched about this SMP brand but I'm not sure if it will be a right choice... Any help is very much appreciated.. Thanks!

Click to expand...

I just did mine a couple of weeks ago. GM Alt, 3 wire, new ramn from NAPA $50. Pig tail plugin from local auto electric shop that has the diode inline $10. Few connectors about $2. Complete rewire and conversion to a starter relay and key switch $50 (making it grandkid safe, not nessary). New lights $30. New Battery $65. Hardware 3 buck So I spent about $180 for a complete conversion with all new wiring and lights.

If you flip the genny bracket over the alt will mount and now cutting of the hood is required.

From what I've seen of the kits I would bother with buying one. Kinda spendy for what yer getting.

Rick