farmall super m 12 volt conversion

Hope someone can help me out... I'm installing a12 volt conversion kit on my 52 super m. The question i have is if also put a 12 electronic ignition in it would that eliminate the need for the resistor block. Anything else I need to change over to 12 volt besides the light bulbs to have a tractor thats entirely 12 volt. Thanks in advance.

To answer that question CORRECTLY without guessing or making possible faulty assumptions based on your limited info YOU HAVE TO CHECK WITH THE VENDOR such as Pertronix or whoever (as they know the switches current rating).


Whether or not you need a voltage dropping current limiting ballast resistor depends on:

1) The current rating of the elec switch.

2) The LV Primary winding resistance of the coil


Theres a chance you may still need some ballast even if not the typical 1 to 2 ohms as it depends on the switches current rating and the coils resistance. With a certain rated elec switch and a certain perhaps after market HV High Energy Coil (NOT the old stock coil) some ballast may be required BUT ONLY THE VENDOR CAN TELL YOU THAT although Billy Bob and Bubba might make a good guess maybe correct??? I believe some high energy after market coils that may still require some ballast depending on the switches current rating and the coil BUT YOU HAVE TO CHECK WITH THE SWITCH AND COIL VENDOR NOT ME OR BILLY BOB.


ALL THAT BEING SAID the typical off the cuff short answer would be:

If you had a ballast before its still used if you still use the old stock coil. If you had one before and its a 12 volt tractor, it must be a 6 volt coil, in which case IT DONT MATTER IF THE SWITCH IS A SET OF POINTS OR A TRANSISTOR you still need to only apply 6 volts to a 6 volt coil or else it will overheat unless the ballast is used. In addition, a 6 volt coil unballasted (on a 12 volt tractor) may cause the switches current rating to be exceeded.

Sooooooooo if youre only changing the switch from mechanical points to an elec switch and are using the old coil and its a 12 volt tractor and had a ballast resistor in place (i.e. prob a 6 volt coil) THEN YOU STILL NEED THE BALLAST.

If youre changing the coil and use a stock type full true 12 volt coil (NOT High Energy high voltage etc ) you probably NO LONGER NEED THE BALLAST.

Got it???

John T

You will need a resistor block if using the existing coil, the Pertronix just really replaces the points and condenser.

I have had mine on 12V for quite a few years now.
When I originally converted it I bought an
internally resisted coil for a Kohler 12hp. engine
like the IH Cub Cadets used to use. I just recently
updated to electronic ignition and while I was at it
I bought the Pertronix 3ohm coil to go along with
the Pertronix electronic ignition kit. When I originally converted it to 12v I also
converted mine to negative ground so that if my
battery were to ever go bad I could jump it with my
pickup truck. I have yet to have to do that.

Ok thanks guys. I think I'll just put the resister block in and leave the points and the condenser in it for now. I also have another question. Will the engine from a m bolt up to the bell housing on a 300 and are the clutch and fly wheel the same if so.

No. The M is larger.

An H engine will bolt up to a 300. It goes H-Super H-300-350.