Still struggling- Farmall M

I don’t really want to convert this over to 12 volt unless I’ve ruined some parts and just keep this tractor as six volts. For several months, since I’ve bought the tractor, its run just fine. The battery that was on the tractor it was a 12-volt (24-5). Never had a problem.

This is what continually gets me confused whether this tractor has been converted to a 12-volt or if a ballast resistor is installed otherwise why would it work on 12-volt (Like I said, electrical is not my area)?

How it started:
I checked the lights and they were all burnt so I changed them. The burnt bulbs were 1 light wire strand and the new bulbs had two wires for dim and bright. After changing the wires to the top lights and the bulbs- everything worked great, lights worked and the tractor started. Later that day it just didn’t start.

Next thing. I Simply pop the foot starter and the battery cable on the positive side of the battery popped. The starter did move or click.

After looking through the wiring diagrams by Bob M, my tractor looks closest to “Farmall H/M stock 6-volt generator w/cutout relay and magneto ignition” but there is a plate mounted on the generator and the wiring around the generator looks more like the one for “Farmall H/M stock 6 volt -voltage regulator mounted on generator and magneto ignition” but I do have lights.

The generator says remanufactured 6 volt and the plate that sits on top of the generator has a spring coil (sits vertical closer to the belt). Is this the voltage regulator? The electrical tabs that the wires connect two are red (if that means anything)

I went ahead and attached a battery to measure electrical currents. I have current to the to the generator even though the wires are exposed. No currenat all to the starter or the magneto. The lights are working.

At the foot starter there are two bolts that the battery and the starter cable are attached too. The bottom one where the starter wire come out, has no current and it turned red the last time I hit the foot pedal (ignition).

Yesterday everything was closed so today I was going to try a new six volt battery with 00 gauge battery cables. Is this the next place to start? Also, it was mentioned to me in a previous post to polarized the generator? Is this still needed?

I appreciate your time very much along with suggestions- Scott

FIX THE EXPOSED WIRES!Thats dangerous!

"No currenat all to the starter or the magneto."

You wont have current to the starter until you push down on the starter switch, you should have any current to the magneto,should only be one wire to the on/off switch.

"I checked the lights and they were all burnt so I changed them. The burnt bulbs were 1 light wire strand and the new bulbs had two wires for dim and bright. After changing the wires to the top lights and the bulbs- everything worked great, lights worked and the tractor started. Later that day it just didn’t start."

You dont need those type of bulbs, but if they work,fine!

1) Since the genny says right on it 6 volts, for now Im gonna go with its a 6 volt and lets proceed with your wishes to make it an original 6 volt system.

2) Since what you call a "plate" on the genny has a spring coil (and I assume you mean only one coil) and ESPECIALLY if it has ONLY 2 terminals and NOT three, Im calling it a Cutout Relay and NOT a Voltage Regulator.

3) If its really a Magneto Ignition, theres no need for any Ballast Resistor nor would it have one SOOOOO OO disregard any of my earlier comments proclaiming it needs a ballast cuz thats ONLY true if it were a battery powered coil ignition. ALSO there shouldnt be any voltage to the Magneto, if it has any wires or terminals, those are only Kill Switch wires which kills the spark if a ground (via an ON/OFF switch) is attached.

4) The 2 bolts you refer to are the mechanical starter switch. The one side is from a big cable to the battery so it should ALWAYS BE HOT but the other side wired to the starter should be hot ONLY when the starter is depressed (its just a switch inside there).

IF ANY OF THE ABOVE ISNT CORRECT I HOPE SOME OF THE OTHER GENTS CORRECT IT BUT FOR NOW ITS ALL I GOT TO PROCEED WITH.

Sooooo oooo, once you get a good and charged up 6 volt battery installed with a new 00 Gauge cable from the battery to the starter switch and another to a good clean rust free soild frame member bolt for ground and you depress the starter we will know more. Ifffff fff when depressed the lights dim wayyyyy down badly and the cables may get warm but she dont crank over, I question the starter quality (or maybe its mechanically stuck n jammed?? rock the engine or loosen the starter n try it) so post back n let us know. However, if the lights dotn dim too much but she still fails to crank I would question the quality of the starter switch IFFFF the cables n grounds n connections are ALLLLL L good. The starter switch may be burned n carboned up inside !!!!! !!!! BE SURE ALL BATTERY N STARTER N SWITCH N GROUND CONNECTIONS ARE CLEAN N TIGHT Especially the one that popped !!!!! !!!!! ! remove n clean n wire brush them alllll lllll lllll

If you wanna use 6 volts on an M, I would suggest the absolute biggest n heaviest highest CCA rated battery you can physically fit on the space plus no less then 00 Gauge batteyr n starter n ground cables.

5) If it is a 2 wire Cutout (one coil 2 terminal) Relay and NOT a 3 wire VR, then the gennys Field post would have to be wired up to the light switch for controling the genny. Do you have a 4 position LHDB light switch??? If so it as a terminal that wirs dwon to the gennys Field post. Check Bob M"s wiring diagrams and what he has to say for better info regarding that n the switch.

6) If it is a 2 wire Cutout relay its BAT side wires up to the ammters load (NOT to battery/starter) side terminal and its GEN side wires to the gennys Arm post.

7) If it is a Magneto theres no ballast nor external coil but if it has a kill wire stud it wires to the tractors ON/OFF RUN/STOP etc switch with the other switch lead wired to ground.

8) YES to be safe I would re polarize the genny, just momentarily flash jump a wire around its cutout relay from its BAT side to its GEN side n you ought to get a lil spark.

REMEMBER This is for a 6 volt genny and a 2 wire cutout relay and a light switch genny field current controller and a Magneto Ignition, Sooooo ooooo o if thats NOT what you have let us know n we will try this again.

Thats the best I have to offer fer now based on my "best guesses" as to what you have.

John T

This does help- I am going to take a digital camera out today and take pictures to be sure of what I have or don't have. Thanks again for spelling it out to me. It helps!

Adam R

Hope you had a good T-Day