Is there any difference between 6/12 V generators? Physical size? internal windings or electrical hookups? One basic question I haven't figured out is a 6 volt generator has the capability of putting out more than 6 volts. It's the 6 volt regulator that "regulates" it to prevent excess voltage going to headlights, heater motors etc. correct? The way I look at it the 6V gen doesn't know its a 6 volt gen the regulator is its brain. Perhaps a 12 volt has larger windings, larger bushings? Why can't I put in a 12 volt regulator in a 6 volt generator system to accomplish the same result as a 12 volt generator system.

 

You can change the field windings to make a 6v a 12v.

 

how do go about changing the field windings? thanks

 

You can put a 12v regulator on a 6v generator and get 12v, but only about 20 amps. If you change the field windings, you can get the full 35 amps.

The field windings are attached to the case with special square-socket screws. There is a special rig to remove them, shops will have it. I'd suggest just buying a 12v rebuilt generator outright, it's a lot easier. I assume you'd also want to convert to negative ground at the same time.

 

not yet was just curious 6volt still works fine thanks

 

The generator windings are such that they are rated for specific output. On these vehicles, voltage is constant (within a given range) and amperage is what increases or decreases with demand The standard 35 amp 6 volt generator would work theoretically with a 12 volt regulator, but it would only produce half the amps (17.5). And because the 6 volt generators will only produce the max output above 1100 rpm, your electrical system would only produce about 5 amps at idle.

In reality, the output that comes off the 6 volt generator will produce more amps but will not produce much more than about 7 volts because of the way its wound. There's not enough wire in the windings to produce magnetic field required for the higher voltage.

Your regulator limits amperage while keeping the voltage regulated in a specified range, and it will cut out when there is insufficient demand. So with a 6 volt generator and 12 volt regulator, the relationship between supply and demand will also be "confused."

The only practical modification to the 6 volt generators was to increase the rated output to 60 amps for heavy duty use. This was done with a heavy duty regulator which allowed more amps at the given voltage by increasing RPM on the generator. There was a kit to convert the 35 amp generators that included a smaller pulley, larger bracket, and heavy duty regulator

 

Thanks Julie I knew you would have the answer. Although I must confess the generator in question is on my 1953 Ford Golden Jubilee tractor but perhaps the information will be useful to others as well. I currently run the 6 volt generator with a 12 volt regulator however, it doesn't maintain the battery in the long run. It must be because of the 7 volts you mentioned. I found what is advertised as a 12 volt generator out of a 60s Ford truck and was curious if there were physical differences between the 6 volts that would prevent me from installing it on the Jubilee. But since this is a truck forum....

 

Well, let me ask you....what volt battery do you have in the tractor? The reason I ask is because if it is a 12 volt battery then obviously you need a 12 volt generator. But being 53 if it's original, chances are it's a 6 volt electrical system. With a 6 volt battery and a 6 volt generator, a 6 volt regulator would probably solve your problem. If you have problems keeping th ebattery charged up with th e6 volt system, try adjusting the regulator cut out up a little higher - the procedure is in the 49-51 Ford Truck Shop Manual and probably in the tractor manual if you have one.

Bob Jones is a tractor guy (bobj49f2) you might want to send him a note!

Usually the generators are very similar - if not the same physical configuration between manufacturers!

 

Bruce,

I wanted to maintain an original look on my '56 860 when I restored it, but also wanted to convert to 12V. The diesel tractors of this era were actually 12V. I poked around and found a generator off of a diesel tractor and put it on. It's a direct bolt-on. Run it with the matching 12V regulator from a diesel machine and it works great.