cut out relay

This is a cut out relay, right? It has two terminals on the one side, not three. But there is an open space between the two, as if there could've been a third terminal there. Why isn't the the F terminal connected to anything? Why would someone disconnect this one? What does it do? This is on a Farmall M. Very hard to start or doesn't start at all. It desperately needs all new wiring and I'm thinking about changing the whole thing over to 12 volt. Maybe. I would really like to get rid of that stupid stupid stupid starting push shaft down by my feet. Would it work to put in a simple push button to start, like on my 666 tractor? Need 12 volt battery to use a different start button like that?

(quoted from post at 07:04:14 08/12/19) This is a cut out relay, right? It has two terminals on the one side, not three. But there is an open space between the two, as if there could've been a third terminal there. Why isn't the the F terminal connected to anything? Why would someone disconnect this one? What does it do? This is on a Farmall M. Very hard to start or doesn't start at all. It desperately needs all new wiring and I'm thinking about changing the whole thing over to 12 volt. Maybe. I would really like to get rid of that stupid stupid stupid starting push shaft down by my feet. Would it work to put in a simple push button to start, like on my 666 tractor? Need 12 volt battery to use a different start button like that?

Click to expand...

(quoted from post at 07:04:14 08/12/19) This is a cut out relay, right? It has two terminals on the one side, not three. But there is an open space between the two, as if there could've been a third terminal there. Why isn't the the F terminal connected to anything? Why would someone disconnect this one? What does it do? This is on a Farmall M. Very hard to start or doesn't start at all. It desperately needs all new wiring and I'm thinking about changing the whole thing over to 12 volt. Maybe. I would really like to get rid of that stupid stupid stupid starting push shaft down by my feet. Would it work to put in a simple push button to start, like on my 666 tractor? Need 12 volt battery to use a different start button like that?

Click to expand...

There's an internal field resistor in the cutout connected to the unused terminal.

On tractors with lighting equipment installed that terminal is left unused, as a wire from the "F" terminal on the generator goes back to the light switch, which has a field resistor, and that's switched in and out of the circuit, to vary the charging rate rate depending upon if the lights are in use, or not.

Whether left 6 Volt or changed over, it's easy to install a starter solenoid and pushbutton.

Thank you, Bob!

The old generator systems were somewhat troublesome if everything was not up to par.

The easy fix will be to convert it to 12v neg ground with an alternator. From the looks of the wiring, a rewire will eventually need to be done. If converting it to an alternator and 12v, the wiring will be simpler, best just make your own wire harness than trying to buy one.

But the starter lever, is that possibly there to prevent starting in gear? If so, that needs to stay. Very dangerous to have a tractor that will start in gear!

(quoted from post at 08:55:47 08/12/19) The old generator systems were somewhat troublesome if everything was not up to par.

The easy fix will be to convert it to 12v neg ground with an alternator. From the looks of the wiring, a rewire will eventually need to be done. If converting it to an alternator and 12v, the wiring will be simpler, best just make your own wire harness than trying to buy one.

But the starter lever, is that possibly there to prevent starting in gear? If so, that needs to stay. Very dangerous to have a tractor that will start in gear!

Click to expand...

n M Farmall will start in any gear you like.

As bob noted the Field terminal on the generator is connected to the light switch for controlling the output for charging. The
light switch is divided into 2 switches internally. One is a power switch to the lights, and the other is a switched ground used
for the generator. They both work using the same shaft, but have no electrical connection. The field in the Delco charging
system is provided voltage inside the generator, and grounded to make it have magnetism. The grounding is through the light
switch at two different rates, One for Low charge through a resistor on the back of the switch, and a high charge rate directly
to ground. The high charge rate happens when the light switch is in H D or B positions. This is to allow the battery to be
charged at about 10 amps to makeup for multiple starts in one day, or when the lights are on Dim or Bright. There is no Off
position for the generator because the cutout relay in the box on the generator turns the entire charging system on and off as
the tractor is running or shut off. Remember the tractor was designed to run pulling implements or running a machine like a feed
grinder for hours. This means the generator (as designed) doesn't work well, or at all, when idling around at low engine speeds.
Common issues with the system are bad cutout relay, bad light switch or light switch ground, and bad brushes in the generator.

Were it mine, and if I was more interested in function and reliability than originality, I would change it to 12v negative
ground, with a Hitachi made 14231 alternator. (fits 1977 Nissan PU) The Hitachi is smaller and is easier to fit. It L terminal
is equal to a Delco 10SI #1 terminal, and the S terminal is Equal to the #2 terminal on a Delco 10SI. It is necessary to put a
resistor in the coil circuit (or a coil designed for use with no resistor. Change the wiring on the coil so the negative small
terminal goes to the distributor, and change out the light bulbs to 12v. The starter can handle the change as is.

IH never had a interlock on starting on any XXX, or Letter series or earlier tractor. Inconvenient yes. Jim

Thanks guys and thanks Janicholson for the details! Looks like I really should make the change to 12V. I think I will.

So I do want to convert to 12V and I've been online looking for parts and these alternator conversion kits for the Farmall M, one says only use with TO20 and the other says only use with TO30. What part are they talking about???? I can't find TO20 or TO30 on any part on the tractor!

Nevermind, it somehow directed me to Massey parts instead of Farmall.