6V gen to 12V

I have a generator that I would like to convert from 6v to 12v. The gen is a 3 brush/3 post gen. I have read that some can be converted by using a different reg, while most need different fields. Which way will I need to go?

I have successfully used a 6 volt genny to charge a 12 volt battery by just using a 12 volt Voltage Regulator NOW DONT ANYONE HAVE A CALF Im NOT saying thats engineering correct and Im NOT saying it charged at any real high rate, Im ONLY SAYING it worked. Theres a chance the 6 volt field coils may draw too much current and overheat but mine never had a problem.... A genny dont necessarily know its output, that depends on how fast it spins and how much field current is pumped through it i.e. the job of a VR or manual Low/High charge controller.

The CORRECT thing to do is have a genny shop change out the fields and anything else necessary.

NOTE if changing from a Cutout Relay to a full fledged Voltage Regulator on a 3 brush genny, one could adjust the third brush to max charge or else just do away with it and convert to a standard 2 brush unit. The VR if correctly matched to the genny will regulate and limit the field current so theres no need for the old 3 brush system and a low/high charge control.

NOTE it makes a difference of course if the Genny is a Class A (JD, IHC, Oliver etc.) or Class B (Some Fords and Masseys) as each require the correct Voltage Regulator

It may be cheaper n easier just to buy a new or used already 12 volt genny and VR and be done with it.

Got any old fashion mom n pop genny starter alternator shops nearby??? Try Kenneth at Classic Generator in Texas

John T

I do have a starter and altenator shop but would like to do it myself.

(quoted from post at 06:53:02 09/03/12) I do have a starter and altenator shop but would like to do it myself.

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Wanting to do it yourself is admirable, but it takes some special equipment and tools to do such a thing, and you won't find those tools and equipment just anywhere.

> A genny dont necessarily know its output, that
> depends on how fast it spins and how much field
> current is pumped through it i.e. the job of a
> VR or manual Low/High charge controller.

You may also want to put a smaller pulley on the generator so it spins faster. Don"t overdo it though, or the belt will slip.

After I posted this I thought what I said didn't add up. The gen has two brushes, not three. The three posts are A, F, and a ground post. The tag says it was made by UP and below that 12 55 GD 72 is stamped below it.

The little Hitachi alternator will fit right up inside the hood, works great.

No problem in giving it a try. I doubt you have the specs as to how much current the fields are designed to carry, thats one of the main limiting factors (fields overheat) when trying to increase a gennys output. Usually the armature can handle the current say 10 amps to 20 amps but its impossible sittin here to know the armatures current rating??? If you try it and damage the field windings (Id say greater chance they overheat instead of the armature but no warranty on that) well heck then you can get a new set of 12 volt fields installed anyway, its NOT their voltage, its how much current they can handle thats critical.

Just be sure to use a Class A VR if its a Class A genny and be sure the VR is compatible with your ground, Pos or Neg and then its your call

John T

That's is the way I did it and it is great

Simply change the genny and reg and all bulbs to 12 volts and be done. Do it yourself no problem. Why do you need to change the system anyway the 6v system works just fine. Beware the starter is 6v positive ground. Use a electrical drawing from a 1955 to 1960 chevy car or truck for reference. Al

> Beware the starter is 6v positive ground.

It"s a series motor. Polarity doesn"t matter. It will also work fine at 12V.

It is improbable the generator will put out 12V at low RPM with a load like lights on. As others have stated, it needs RPMs and field.

The reason I would like to change it is I want to have lights on the wagons when I pull them. Since my other tractors are 12V the wagon lights (some of which may be replaced with LEDs) are setup for 12V. But I would like to keep the Gen look.

I have a 2N Ford that someone had converted to 12 volts before we bought it, everything except the generator. A new 12 V regulator and a smaller pulley on the generator and it works well. Plenty to run the three lights and engine.

Very good reason and I like the LED idea also. Good luck Al

Thanks for the info. Al

Do you run without the hood? Unless you do, the tractor "looks" the same, generator or alternator.

It won't cost you anything to try other than the 12V regulator, but odds are not good that it will work. The generator will probably put out enough to maintain the battery, but when you add lights, the load will be too high.

I you have not already checked you may want to see if the LEDs will work on 6 Volts. LEDs want 1.5 to 3.0 volts across them so they must have either a resistor or some sort of voltage regulator to limit voltage/current. I have found that in many cases the brighness is satisfactory at reduced voltage levels.

You may be able to upgrade your wagons to LED lights for less than converting to 12 volts.