51 Deere B-is this an alternator or generator?

[RickB]

'51 JD B came from factory with a 6 volt electrical positive ground electrical system. If changed to alternator it will need to be changed to negative ground as there are very few positive ground alternators.

Additionally a JD B might not turn a one wire alternator fast enough to self-excite.

 

[mitch becton]

as i have mentioned before if you have a low rpm tractor and have access to a local rebuilder have him install a transp 10ac regulator which activate as low as 500 rpm it comes in a kit with instruction if you want to try yourself i have several rebuilders i sale to this is all they use because rpms are very low to make it work

 

[Ivan49]

Take that gen off and have it tested. They made a 12 volt gen that looked like the 6 volt one. It appears to me that that gen has been added at a later date. The factory gen does not stick out past the hood that far.

 

[mapper]

If the RPM is too low to self excite, you can set up a simple system to excite the alternator at low RPM. One of the contacts in the two contact receptacle is for that purpose. Use an oil pressure idiot light switchto control it. It will apply 12 volts from the battery when the tractor starts and shut off the current as soon as the oil pressure comes up. Make sure this is connected to the ignition switch so the battery is not discharging when the tractor is shut off. A momentary contact button switch will work as well.
My neighbor has an old allis chambers tractor with a magneto ignition that he added a alternator to to keep the battery charged more reliably than the mag. He showed me the oil pressure switch trick.

 

[ndgregor]

Thanks for all of the feedback. After further disassembly, it was clear that someone added this on at a later date (homemade mounting arrangement). I have tested it and it appears to be a fully functional 12V generator.

 

[airbiscuit]

If it hasn't already been done, you will probably want to replace the light bulbs with 12V versions.

 

[CADplans]

If it hasn't already been done, you will probably want to replace the light bulbs with 12V versions.

Whats the matter,, you do not like flash photography??

:laughing:

I put a 12V bat/gen in my 46 Willy's Jeep farm run about,,,

we did not bother with lights,, just use a flashlight,,, :thumbsup:

 

[mitch becton]

as mentioned already it is 12volt almost any american made auto/truck/farm 6volt generator can me made into 12volt by changing the field coils and regulator