Converting from 6 to 12 volt

[Ozark 65]

I am new here and I am trying to help my dad with his 1951 MT John deere. I have a one wire alt and 12 volt coil. I am just not sure of the wiring. Most of the wires have been removed or just partial wires. I found a picture of the wiring in 6 volt and I was wondering what do I need to change from the original wiring. I attached the diagram that I found.

 

[Bob Bancroft]

I am new here and I am trying to help my dad with his 1951 MT John deere. I have a one wire alt and 12 volt coil. I am just not sure of the wiring. Most of the wires have been removed or just partial wires. I found a picture of the wiring in 6 volt and I was wondering what do I need to change from the original wiring. I attached the diagram that I found.

What condition are the wires in? I can't imagine very good. This would be a good time to start over with all new wiring. "wiringharnesses.com" can make a wiring harness for your new arrangement with the alternator.
One thing old tractors have in common is lack of protection. Your negative battery terminal will be your ground cable. (Starter doesn't care either way) Power emanates from the positive terminal on the starter. Do yourself a favor and make sure there's a fuse or circuit breaker close to there, so the whole system, outside of the battery cables, is protected from short. That could well be incorporated into a new harness.
With a negative ground system, the negative side of the coil goes to the distributor. Do yourself another favor and make sure the advance mechanism is free to work. And lubricate the hole in the top of the shaft under the rotor with light oil, as well as the main shaft, if there's a plug in the distributor housing you can remove. These are just a few ideas, I'm sure plenty of detail will follow.

 

[Mark Poss]

Pretty sure you’re going to need a 12 volt voltage regulator also

 

[JMOR]

Pretty sure you’re going to need a 12 volt voltage regulator also

Nope! VR is built into his stated “one wire alternator”.

 

[Ozark 65]

What condition are the wires in? I can't imagine very good. This would be a good time to start over with all new wiring. "wiringharnesses.com" can make a wiring harness for your new arrangement with the alternator.
One thing old tractors have in common is lack of protection. Your negative battery terminal will be your ground cable. (Starter doesn't care either way) Power emanates from the positive terminal on the starter. Do yourself a favor and make sure there's a fuse or circuit breaker close to there, so the whole system, outside of the battery cables, is protected from short. That could well be incorporated into a new harness.
With a negative ground system, the negative side of the coil goes to the distributor. Do yourself another favor and make sure the advance mechanism is free to work. And lubricate the hole in the top of the shaft under the rotor with light oil, as well as the main shaft, if there's a plug in the distributor housing you can remove. These are just a few ideas, I'm sure plenty of detail will follow.

Thank you very much. I will look into the wiringharnesses.com sounds like that's a great place to start.

 

[Ozark 65]

Pretty sure you’re going to need a 12 volt voltage regulator also

My alternator has a internal regulator. from what I understand that will take the place of the external voltage reg.

 

[buickanddeere]

Those vertical engine two cylinder Deere operate just fine on 6V and a generator . The exception being the 440ICD, 440ID and 435.

 

[BarnyardEngineering]

An MT is a pretty simple tractor, wiring wise. You can wire it yourself using this basic diagram. The ballast resistor is only necessary if you don't replace the coil with a "12V No Ballast Resistor Required" coil:

 

[Ozark 65]

Those vertical engine two cylinder Deere operate just fine on 6V and a generator . The exception being the 440ICD, 440ID and 435.

I agree but the gen bracket broke and the gen quit working so we were just going to switch it over.

 

[Ozark 65]

An MT is a pretty simple tractor, wiring wise. You can wire it yourself using this basic diagram. The ballast resistor is only necessary if you don't replace the coil with a "12V No Ballast Resistor Required" coil:

View attachment 102818

This is just what I was looking for thank you so much.

 

[BarnyardEngineering]

Those vertical engine two cylinder Deere operate just fine on 6V and a generator . The exception being the 440ICD, 440ID and 435.

I agree, they do, but it always seems like a constant fight to keep those 6V systems working. The batteries never seem to last, and it's always a butt-clenching affair to jump start them (e.g. last time I jump started Dad's H the battery started boiling the moment I connected the 12V jump to it, I bought a new 6V battery immediately... there are easier ways to become a horribly disfigured supervillain).

 

[560Dennis]

some additional information available

https://forums.yesterdaystractors.com/pages/artint131/