Visual Check if 6 or 12 Volts

Anonymous-0 · Jan 6, 2009

How can I quickly look at a tractor and tell if it is 6 or 12 volt generator? It is obvious if has been converted to an alternator but how can I tell if it still has a generator without doing any testing?

tcanthonyii · Jan 6, 2009

Don't let the alternator fool you. My grandpa has been putting 6 volt alternators on tractors and model a's for years.

T.C.

IH2444 · Jan 6, 2009

And some generators are 12 V.

rrogers · Jan 6, 2009

look up a parts number off one of them

Anonymous-0 · Jan 6, 2009

I know that some tractors that came as 6 volt generators from the factory have been converted to 12 volt generators. My question again is how can I visually tell the difference?

tcanthonyii · Jan 6, 2009

As rrogers said...look at the serial numbers. Visually there really isn't a difference that's I've been able to see.

T.C.

JMOR · Jan 6, 2009

If it is up & running and the ammeter properly indicates charge & discharge with load & speed variances, then if it had a 3 cell battery, I would declare it 6v & if 6 cell, 12v.
If it is the 60's vintage Delco generators, you can go by red vs black tag unless it has been modified.

Anonymous-0 · Jan 6, 2009

you could look at the batt.for one thing.6v. has 3 cells 12v.has 6 cells.this would give a good indication of the charging system on it.

Hugh MacKay · Jan 6, 2009

Retcol: My Farmalls 560 and 656 came new from the factory with 12 volt generators. My 1953 Farmall Super A has been equipped with a 6 volt alternator for 20 years now. Quick is a volt meter.

If the tractor your looking at has a battery, 6 volt will have 3 cells with 3 removable caps. 12 volt is very likely sealed or 6 cells and 6 removable caps.

rrogers · Jan 6, 2009

the identificationnumber is usally on a oval badge on the genorators. if it's been painted over a little brake parts cleaner and light rubbing with steel wool should clean it off pretty good. some times it's just stamped on it same with alternators

-Randy-

Bob · Jan 6, 2009

Delco 6-Volt generators have "black tags" and Delco 12-Volt generators have "red tags".

This MAY be of some help if the generator still has it's original tag AND has not been molested internally.

Anonymous-0 · Jan 6, 2009

Use a volt meter on the battery if you dont know the difference between 6 or 12 batts.

Anonymous-0 · Jan 7, 2009

I can tell the difference between a 6 and 12 volt battery. However, it is difficult to determine when there isn't any battery.

Nebraska Cowman · Jan 7, 2009

You can't. The best you can do is an educated guess based on what others have said. I assume it is as came from the factory until proven otherwise. Most older Farmalls were 6 volt positive ground. Post the model and somebody will tell you.

mkirsch · Jan 7, 2009

(quoted from post at 04:49:51 01/07/09) I can tell the difference between a 6 and 12 volt battery. However, it is difficult to determine when there isn't any battery.

The answer is, there is no 100% sure way to tell just by looking, then.

If there's no battery and the tractor was originally 6V, then the best you can do is ASSUME the generator is 6V and go from there. Further research and testing will confirm the generator's true identity.

Having a 6V alternator or a 12V generator on a tractor originally equipped with a 6V generator is extremely rare. The overwhelming majority of conversions were done with 12V alternators because:

1. 12V alternators are cheap and widely available. 6V alternators are sometimes tough to find, and 12V generators are expensive.
2. 12V "solves" the starting problem. A 6V alternator only eliminates the reliability issues of 6V generators.
3. 12V generators have the same reliability issues as 6V generators. Of course the reliability problems are more of a maintenance issue, but alternators are practically maintenance-free.

Tractor owners generally convert to solve two issues, the reliability problems with generator systems, and difficult starting.

Anonymous-0 · Jan 7, 2009

It is a Farmall Super C. It came from the factory as a 6 volt with positive ground. The tractor has a generator on it but I am unsure if it is 6 or 12 volt because nowdays so many have been changed.

Nebraska Cowman · Jan 7, 2009

It's probably 6. Cs don't start hard. Actually you can make the gen charge either by tweeking it a little and maybe changing the regulator.

rrogers · Jan 7, 2009

To save a lot of head scratching you could just take it off go to autozone and the can test it for you. It wouldn't take more than a few minutes and then you would know if it is still good as well.

-Randy-

Hugh MacKay · Jan 7, 2009

Mkirsch: there is nothing rare or expensve about 6 volt alternators, nor are they hard to find. it's nothing more than changing two wires within a GM Delco Alternator. When I bought mine, the over the counter sales guy changed it in less than 5 minutes. I walked out the door with a 6 volt alternator, same price as 12 volt. I expect other brand alternators are quite similar.

Hugh MacKay · Jan 7, 2009

Howard: Right on, "these little engine start very easy". A well tuned and maintained 6 volt, C-113 or C-123 engine will start at -40 F or C anytime.

mkirsch · Jan 7, 2009

(quoted from post at 06:52:33 01/07/09) Mkirsch: there is nothing rare or expensve about 6 volt alternators, nor are they hard to find. it's nothing more than changing two wires within a GM Delco Alternator. When I bought mine, the over the counter sales guy changed it in less than 5 minutes. I walked out the door with a 6 volt alternator, same price as 12 volt. I expect other brand alternators are quite similar.

Okay, cool to know. In my research, I've only come across a few units advertised as 6V alternators, and they were around $150.

Hugh MacKay · Jan 7, 2009

Mkirsch: I know all about what your saying, and $150. is low compared to some quotes I've heard. I had a friend tell me he was quoted $250. I made a point of going to that shop, asked for a 6 volt GM Delco alternator. Bingo, they were getting even higher $265. Then he tore into a 5 min oratory using big long words, how complicated it was to create a 6 volt alternator. This was in front of about 8 of his customers. I asked, "Do you screw all your customers this badly?" Well, you could have heard a pin drop, then I explained exactly how difficult it really is. Then I walked out.

Hit a site, Alternators by Quick Start.

NDS · Jan 7, 2009

Back in sixtys we were running several 12 volt generators, still have couple of them on M and 400. Do not know exactly what is required to go to 12 volt generator but shop we used would rebuild one to 12 volt far about same price as 6 volt.

tcanthonyii · Jan 7, 2009

265 for a 6 volt is high. Grandpa picks them up somewhere for about 150 bucks.

http://store.alternatorparts.com/alternators6voltpositiveground.aspx

That place has them for around 150 and up to 200. Not a bad price if you ask me.

Hugh MacKay · Jan 7, 2009

I can still buy 6 volt alternators new for around $65. I didn't pay the $265., just wanted to teach some unscrouplous vendor a little lesson in front of his customers.

scotc · Jan 11, 2009

Or you get lucky and just change the battery. Then add a resistor. I got one for an 85 dodge v8 pickup. SM.

Visual Check if 6 or 12 Volts

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