to convert to 12v or not

I have a 1959 Ford work master 641.
Needs wiring harness. Is the harness in a 12v conversion kit a complete harness -lights?
I will replace points with electronic ignition.
What are the advantages and disadvantages of 6 v-12v,positive or negative ground.
The tractor is now 6v+ground.
What about gage & coil?

Thanks!

I converted the Cockshutt 50 to 12 volt neg ground years ago and it sure makes it start quicker. But starter gear and ring gear are taking a
beating since this tractor always had a little problem with grinding gears even on 6 volt. On 12 it spins faster and also grinds worse. For
that reason alone I'm considering going back to 6 volts and just using a big diesel six volt battery. I have the original 6 volt system on
the Cockshutt 40 with a big battery and it starts very well.
One advantage to 12 volts is that it is easier to find another 12 volt battery if the one on the tractor quits suddenly.

I converted my Ford 600 to 12 volt last year, I should have done it sooner, starts way better and faster and idles
better, you will have to replace headlight bulbs, I just unhooked mine because I never use it at night.I can
switch batteries with other 12 volt systems like my other tractor or even my pickup, I can run my 12 volt sprayer
now instead of using the larger tractor.

"Needs wiring harness. Is the harness in a 12v conversion kit a complete harness -lights?"

Doesn't appear to have light wires. And does not say what type alternator it is wired for. I would give them a call, ask some questions as to the alternator connections, what exactly it includes. For $17, don't expect much.

"What are the advantages and disadvantages of 6 v-12v,positive or negative ground."

Advantages: Faster cranking, standard battery, standard accessories, alternator gives faster recovery, eliminates point type regulator.
Disadvantages: Can be hard on the starter drive and flywheel gear, no longer original.

It will need to be negative ground for the alternator. Once converted to negative ground, be sure everyone knows that might be charging or jump starting. Also the electronic ignition is polarity sensitive, could be damaged if reversed.

"What about gage & coil?"

You will need to reverse the polarity of the amp meter (I believe the oil and temp gauges are mechanical, if equipped), reverse the polarity of the coil, and add a 1.5 ohm resistor if you want to keep the original coil. If you go with a 12v coil, be sure it is a 3 ohm coil. All lamps will need to be changed to 12v.

You will stir up a hornet's nest here with your question. I have changed 2 tractors from 6 to 12 volt- grnd with an alternator. Both tractors also have EI. My 430 JD never cranked very fast on 6 volt. I had a generator go bad on my MT so swaped the generator from 430 to it. I think I got an alternator from a wrecking yard, but even new they are cheap. It starts really great now. I do use lights and much easier to find 12 volt lights than 6 volt, and the alternator keeps the battery up even with several lights. My other conversion was an SMTA. I had experience with Farmall Ms before that generally cranked really slow so converted it. With it I used a resister ahead of the coil until I converted to EI then went with coil Pertronix suggested. The 430 had a fairly new coil with internal resister so used it that way when converting to EI. Make sure you get the right unit for you voltage and ground on the EI as they don't like to be fed the wrong voltage or polarity. My guages worked ok as they weremanual, just put 12 volt bulbs behind them. If you have a fuel guage that may be different. There are several good wiring diagrams in archives her, I used the one by Bob M. Generally not to hard to figure out alternator mount, on the SMTA I just turned the stock one upside down.

The wiring on these old tractors is pretty simple. Plus any decent parts store can get wire in about any color you want. I've converted 3, 2 8n Fords and a Farmall M. I haven't had any problems with any of them and yea, I use lights. Most tractors that old use mechanical gauges and the only conversion there is reversing the Amp meter. I made my own wiring harnesses.

One of the reasons I changed over besides cold weather starting was compatibility. Family members are not too familiar with 6 volt positive ground systems. So this eliminates the possibility of them hooking anything up wrong. Win, win cause 6 volt batts are getting expensive! Plus it's to the point that you have to shop around to find a charger that does 6 volt.

Rick

My Jubilee and Farmall C both were converted to 12v
before I bought them. Both sheared off starter
drives in the winter. Both have rebuilt engines,
excellent compression.

I dug out sheared off parts from bell housing of
Jubilee form about 10 previous broken drives. My
final straw on the Jubilee was when it broke off the
face of a tooth on the starter ring. That's when I
invested in a new 12v starter instead of
overpowering the OEM 6 v starter.

I wasn't able to find a 12v upgrade starter for
Farmall. That's when I decided to take my oldest and
weakest 12v lawn mower battery and under power the
6v starter. Farmall has a mag, so that wasn't a big
issue. Been using the old mower battery for 4 years.
I think the battery is 10 years old too.

One problem people don't think of when going from 6
to 12 v is changing coil to 12v or wiring a way to
bypass ballast resister during cranking.

No way would I want to use 6v starter on 12v. No way
would I want to find a stronger starter drive and
take out more teeth on starter ring.

So if you are don't like the slow cranking 6v
battery, change to 12v. Go the extra expense and
change starter too. About $150 from YT. I love my
12v starter every time I start the Jubilee and I
bypass the ballast too during cranking.
geo

This is a simple conversion, can make your own harness if wanted.

I would recommend updating the starter drive to the newer type, they do not seem as rough on the ring gear.

My dc case was changed over to 12v in the
mid 80's and still works great, starts much
better. A single wire alternator is an easy
change too. Still has the original 6v
starter on it altho I did need to change the
starter drive a couple years ago and the
ring gear this spring. But the ring gear was
original from 1953 and the starter drive was
at least 30 years old.

Bingo, George.

Operating a 6V starter on 12V is very hard on starter drives, ring gears, and, depending upon design, starter nose cones.

Dean

What voltage battery is in your daily
driver, wife's car, motorhome or camper, 4
wheeler, snowmobile, motorcycle, lawnmower
or boat if you have them? Why have an
oddball battery that can't jump anything
else or or be jumped without special
precautions?
6V still uses an antiquated system of a
generator and electromagnets and contact
points to regulate the voltage. That was
fine in 1936 but isn't half as long lived
or reliable as an alternator with solid
state voltage regulator. An alternator
will put out much more amperage than a
generator and will charge at idle.
Generator will not.
12V lets you run all kinds of modern
lights, pumps, gew gaws and doo dads on
your tractor.
12 V batteries are cheaper and much easier
to find than 6 V batteries.
As for EI, there is nothing built today
that still uses points. Nothing!
If you like the idea of set it and forget
it EI is the way to go.

My 641 was 12v, sort of when I got it. Had a 12v battery in it connected to ignition system but alternator was not connected at all. I am happy with 12v. I use the lights and horn I installed. Once connected the alternator keeps battery charged. The EI really seemed to smooth out the engine. No problem starting it.

If you use a new 6V harnesses with your 12V conversion you will have a extra wire to use for headlights. Head lights can be one are two wires depends on if you think you need a decanted ground for the lights...

Your tractor was born to be converted

I converted my Super C about 10 years ago. Now I got a flywheel that's bad in one spot and the starter doesn't engage their. Its the same spot where the tractor stops every time I shut it off. I either hand crank it or move the motor a bit with the crank and then start it with the starter. I guess the starter messed up the flywheel by engaging to quick because of the 12 volt convert. At least that's what I heard so it must be true in my case.

On the farmalls your using the wrong starter drive. Thats all that you are doing wrong. I have converted well over a 100 Farmalls from A through super M with no problems at all, unless the wrong starter drive is used. If your Farmall C has a good strong engine, a lawn mower battery will have problems when the temp drops. Your making moutains out of mole hills.

I'm usually a purist when it comes to converting to 12 volts. If it was made to run on 6v then that's what it should be. Well I have changed my tune a bit even though I think an alternator on an old tractor looks ugly. Little tractors like Farmall B's should start well on 6, there is no reason to convert them to twelve. However I don't see why the tractor companies didn't equip larger tractors like Farmall M's, Oliver 88's with 12 volt systems from the factory, especially when they had live hydraulics and PTO dragging along. By 1958 all tractors should have been 12v. My vote is to go 12 volt.

If I was looking for a tractor like that and it was advertised when I got there and found it was converted over I would just turn around and leave, never lookt it over any more. Repair as supposed to be with points.

If you went to look at a new gas powered tractor today, would you consider one that came from the factory with a 6v generator system and points ignition? You'd expect them to sell about 2 of them because the maintenance on those systems would be too costly, especially when equipping one would cost as much or more than a modern system.

There is a reason tractor manufacturers started with 6v systems, and a reason they abandoned them for 12v, and very good reasons they abandoned 12v generators for alternators. There is a reason they abandoned mechanical points for electronic systems. These things are called "improvements" because when properly implemented they work better than the former technology and increase productivity and efficiency. Just look at the Farmall A (1939) to 140 (1974) saga. If it had hung in there another few years, it would have been not only 12v alternator, but EI as well, and if they were still made today, they'd have full syncro trannys and EFI, because these things make for more useful and efficient tractors with far less maintenance.

Shops have regularly "retrofit" new improvements to older tractors to make them better suited to the needs farmers had for them - bigger pistons, better heads, higher output hydraulics, even things like duals ("they didn't come from the factory like that, so it's just wrong!")

Yes, you can get by running the 6v starter on 12v. A lot of people have and have had no problems. Shortly before I changed my SA to 12v, the starter was giving out (spent a summer hand cranking it, which sealed the conversion before winter), so had that rebuilt with the 12v field coils and new bendix. Works great and glad I changed the system. I can now run lights (and jump other vehicles buried in snowbanks on frigid days) with ease.

Above all, this is Your tractor. If it's a restoration, you'll want to keep it at 6v, or at least keep the parts to change it back. If you're using it for work, make it work for you in the best way you can.