TO20 Electrical Questions, 6v/12v

I'm gradually working through the electrical system on my recently-acquired TO20 and still trying to pin down exactly what I've got here. The battery was stolen from the tractor sometime during the past two years, so that's of no use in identifying what's going on. The widow I bought it from proudly pointed out the tractor still had its original 6v electrical system and I can see where she got that, with the coil being clearly marked as such:






In comparing my wiring to the 6v diagram, I see no reference whatsoever to there being a resistor used in this system. Look inside the red circle at the top right of this photo. Hmmm:






Just a few minutes ago, I was reading through some technical articles over at fergusontractors.org and ran across the following details:

[i:6c0d65e996]CONVERTING A 6 VOLT FERGUSON TRACTOR TO 12 VOLT (using a 12 Volt Generator)

1. Secure a 12V generator (Delco models 1100359, 1100362, 1100434, 1100435, 1100529, or 1100998 will fit and you can use the same mounting bracket). [color=blue:6c0d65e996](My ID tag has thus far proven illegible, so I don't know what I've got)[/color:6c0d65e996]

2. It is best to replace the 6V coil with a 12V unit with a built-in resistor. [b:6c0d65e996]An alternative is to continue to use the 6v coil and add a ballast resistor in the line from the ignition switch to the coil.[/b:6c0d65e996]

3. You will need a 12V battery. Ground it negatively.

4. Reverse the wires on the terminals of the ammeter.

5. It is not necessary to replace the starter with a 12V unit. Just don’t crank the starter for long periods of time as it will heat up a bit sooner than a 12V unit will because of the extra voltage.

6. If you have lights you will need to change the lamps in the headlights and work light and the bulb in the taillight to 12V. [color=blue:6c0d65e996](My lights are all disconnected!)[/color:6c0d65e996]

7. You should polarize the generator, particularly if it has been unused for a long period.[/i:6c0d65e996]


I'm thinking the questions to ask at this point would be:

a. Is there any reason a resistor would've been added to a 6v system aside from the explanation above?

b. Is there a way to test or otherwise identify a static generator to determine if it's 6v or 12v?

c. Is there something simple or painfully obvious you more experienced fellows see in the photo that suggests what voltage I'm working with here?


Thanks in advance for any help. John

Start with this question. Are you looking to make a good working tractor or going for a restoration? If a restoration then you would be looking for the 12
volt generator and regulator, switch to a 12 volt coil and it will have the look of the 6 volt system but upgraded. Or, make it a daily driver, work tractor,
add an inexpensive single wire alternator conversion, 12 volt coil, simple wiring and very reliable. Out the door about $150 or less. A lot cheaper than
finding the 12 volt generator.

I have had my TO30 for 15 years now and had the original generator rebuilt a couple of times, replaced regulators, bought new battery?s every year or
so and finally switched to an 8 volt system with 8 volt alternator. My to35 I switched to an alternator with tach drive and works great. I?ve put single wire
alternator systems in two other TO30?s and they all work great. Email me for any info

It would appear to be converted to 12 volts. But the question is, how complete is the conversion? It is acceptable to use a 6 volt coil with a 1.5 ohm resistor for a 12 volt system. You can also use a 6 volt starter with a 12 volt conversion(I have a one like that). Just crank for short bursts.

If you remove the starter and generator, you should find some info or part number to confirm. A 6 volt generator on a 12 volt system will "work" but slowly drain the battery. But, you do need a 12 volt regulator or it will burn out. See if there are any markings on the regulator.

I can say with certainty, there is no reason to add a resistor to a working 6 volt system. So, you can go ahead and put a 12 volt battery in and see what happens.

With the resistor it most likely had a 12 volt battery

If it were mine I would get it running before worrying about the charging system. Unhook the generator/regulator, and connect a 12 volt battery. If + post on coil goes to side of distributor connect battery positive ground. If -- post on coil goes to side of distributor connect battery negative ground.

Sounds like it has been sitting for a couple of years so at this point the charging system is likely the least of your worries.

Once running, I would expect to find problems with voltage regulator, and if so I would replace generator/regulator with a Delco 10SI 3 wire alternator for about $35 plus core and the coil/resistor with NAPA IC14SB or equivalent direct 12 volt coil and eliminate the resistor. I would also replace any old, brittle, cracked wiring.

Thank you guys for all the helpful info! I have a better understanding of this setup, now.

(quoted from post at 07:59:11 12/13/18) Start with this question. Are you looking to make a good working tractor or going for a restoration?...

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I'm intending to get this one back into service and use it as my "around the house" tractor. It will see some mowing, garden work, light grading, bringing in wood, and that sort of thing. I need to research the single-wire alternator conversion you mentioned because I can really appreciate some cheap and easy.

(quoted from post at 10:12:03 12/13/18) ...I can say with certainty, there is no reason to add a resistor to a working 6 volt system. So, you can go ahead and put a 12 volt battery in and see what happens.

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I don't see what a 12v would hurt as long as I don't just grind on the starter and overheat things. At this point, I'd just like to get the engine started for a more thorough assessment of what needs to be done. Even in decent sunlight I was unable to find anything in the way of part numbers on the generator or starter and the regulator is sufficiently covered in rust and brush paint to conceal anything that was ever written on it. Here's a couple of pics of the generator:

(quoted from post at 11:24:29 12/13/18) If it were mine I would get it running before worrying about the charging system. Unhook the generator/regulator, and connect a 12 volt battery. If + post on coil goes to side of distributor connect battery positive ground. If -- post on coil goes to side of distributor connect battery negative ground.

Sounds like it has been sitting for a couple of years so at this point the charging system is likely the least of your worries.

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Good points. It's sounding more and more like an in-depth 12v conversion is probably in my near future. Thanks for pointing out how to determine the +/- ground of the system based on the coil wiring. If I ever knew that, it's been forgotten for quite some time! Here's a photo of my coil/distributor connection:

There appear to be ID tags on both the generator and starter in your photos. With some careful cleaning those tags should provide info to ID them.

(quoted from post at 20:01:32 12/13/18) There appear to be ID tags on both the generator and starter in your photos. With some careful cleaning those tags should provide info to ID them.

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I was a little excited by those ID tags when I first saw them, but closer inspection has dimmed that excitement considerably. Both tags have suffered impact damage (think something light tapping against them repeatedly) and oxidation to the point that they're mostly illegible. On the generator tag I can just make out "Remy" and the stamped "OD11" on the right side, but that's about it. I was thinking the tags' stamp impressions may be readable from the back side and for a restoration project that would probably be my next strategy. My wife works for a big electric motor repair shop here in Louisville and I may just send the starter and generator in with her at some point. Those guys can tell you most anything about components like this in very short order.