JD M 12 volt system

[george baker]

What are the pros and cons to converting to a 12 volt system on a 1948 M. I am considering the conversion but everything seems fine on my 6 volt system.

thanks

 

[730d se]

George,

If it is working, I would leave it original. The cut outs are still available, other than the generator going bad, that is the only part that could fail.
If you do change to 12 volt, you really should convert to a 12 volt starter.
So the pros would be that it would spin faster on start up. The cons are that you have to spend money that is not needed and it would no longer be original which lowers the value no matter what some folks say.

 

[d. coleman]

if you convert, dont forget to add a ballast resistor to your ignition system to keep points and coil at 6 volts. also the starter will work on 12 volts as long as you don't motor it for long periods between cooling cycles. dont forget to change light bulbs to 12 volt. my 48 "M" is doing great on 6 volt. save your old generator, they are sought after items. good luck, d. coleman(48M&51B)

 

[John T]

George, its one thing if you have a larger harder to crank tractor, but that lil M can in general start fine despite cold temperatures at 6 volts. The only pros may be if its like 20 below 0 and the engine is in bad shape and must starting is of major importance....... If you convert to 12 volts its NO LONGER ORIGINAL,,,,,,BUTCHERED UP JURY RIGGED IGNITION,,,,,,perhaps an unsightly grotesque alternator even YUKKKKKKK,,,,,,,,,Can be tough on starter drives unless the starter is rebuilt for 12 volts,,,,,,,,,,,Lights and voltage regulators or cutouts arent original anymore,,,,,,,,,Collectors or Correct Police may "horse laugh" you at shows etc etc.

If kept at the original 6 volt the genny and cutout relay and ignition components are all standard and easy to purchase and replace.

I really see no reason to convert an M (unlike maybe a big hard to crank tractor that MUST start in extreme cold temps) to 12 volts. However, I still recommend the use of a big heavy duty high CCA rated battery and at least 0 better yet 00 gauge battery n starter n ground cables..Ask the Frankster about his use of Optima AGM batteries in 6 volt tractors, I think you can get them at near 1000 CCA which packs a real wallop in a 6 volt battery compaerd to any lead acid units..

Its your tractor and your choice, however, but you asked for opinions n you get plenty of them on here lol

Best wishes

John T

 

[Hayfarmer]

If it works ok now I wouldn't change it to 12 volts. I have a MT that starts great on 6 volts and I wouldn't think of changing it over. I also have a 430 that was always a slow starter, I used it everyday in the winter to feed cows or plow snow so needed it to start easily. I converted it to 12 volts with alternator and would never go back. I also put electronic ignition on it. A plus to the conversion is that you don't have to try to find 6 volt lights if you use it in the dark(which I do). I also converted a SMTA Farmall to 12 volts. I saved all the old parts if someone wants to send it back some day. I use it on a baler and often bale at night. I run lights on the baler and tractor and have no problem with alternator keeping up. Both of my tractors are "workers not showers" so I don't worry about the "correct police".

 

[Butch GA.]

John T
why do you assume that all conversions are butcher jobs. I have a 48 M converted to 12 volt the alternator is under the hood just like the generator was using the same belt. I also used the same ignition switch with all wiring hidden. I don.t care what the "CORRECT POLICE" say or anybody else for that matter because my M is a working tractor.It doe's go to shows and parades when I feel like cleaning it up. and that's just my opinion

 

[alabamafrog]

My 51 MT works very well with its factory 6v system still intact. I mowed 140 acres of hay and planted/cultivated with it for many years with no issues of any kind pertaining to the battery or electrical system. I have not found any cons but I also don’t crank it in sub zero temps, I don’t go outside in subzero temps.
I don’t understand the tendency for folks to swap voltage and/or swap from the genny to an alternator. I was at a show yesterday and most of the tractors there had an ugly GM alternator hanging off the side with wires ran everywhere. It was a real disappointment to look at a pretty Johnny and then walk to the other side and see that. Now I know that it is possible to do a clean conversion, but why, where do you draw the line. Swap the voltage, swap to an alternator, swap the ignition to electronics, add power steering, add a bucket seat, swap the engine to a modern diesel, jack it up and put a new tractor under it?

 

[george baker]

thanks guys, I thought this was a simple one.
Actually I dont plan on using this much or at all in the winter so i guess i will stick with the six volt system for now unless a part fails.

 

[M-MAN]

George;
If it's working good, leave it alone.

In my opinion if it's a worker it needs a 12volt alternator. If it's a showpiece, it should remain stock. JMO

My M is a worker and I converted it some 25+ years ago. The 6v system was a PITA for me. 6v batteries woulden't last over a year back then & it wasn't practical to keep it 6 volt's when it woulden't work when you needed it to. I coulden't care less what anyone else think's of my M because it's mine & as long as I'm breathing it isn't going anywhere.

I know most of the guy's prefer 6v orig system's, but I'm not a collector and I don't have a bit of use for them on a worker. I've had to push start way to many 6v cars & roll off to many tractor's to ever be fond of them.

 

[Cameron Smith]

If you let it sit for the winter, disconnect the battery and/or keep a trickle charger on it. If it is kept charged, it should last a loooong time!