Electrical Problems

I need some help. I have a Super C and an M. I converted them both to 12 volt with single wire altenators, of course negative ground. Neither one of them hold a charge. The alts are testing out out at 14.3 volts. The M is strictly for pulling so I've taken off everything electrical. I ran the wire from the alt to the switch then back out to the battery. On the Super C, the wire runs to the amp gauge then to the switch and back to the battery. What is going on?

Some single wire alternator need some good rpm"s to get them excited. Try reving the engine and get an alternator pulley that is around 2 1/2 inches in diameter. This will give the alternator more rpm"s.
Did you test the alternator on or off the tractor?

Single wire alternator can also drain a battery if the tractor is not used alot.
Either disconnect the battery when not in use or get a battery disconnect switch.

You can also get a heavy amp switch and put it in the alternator line so you can turn off the alternator when not in use to prevent it from drawing off the battery.

Using a standard Delco-style alternator and adding ONE wire and a simple diode or "idiot light" would solve the problem.

<img src = "http://i167.photobucket.com/albums/u125/27Grainfield/424IH/Alternator%20Stuff/AlternatorHarnesssd.jpg">

<img src = "http://i167.photobucket.com/albums/u125/27Grainfield/424IH/Alternator%20Stuff/AlternatorHarness31.jpg">

I had the same problem on my H, so I'll explain my solution and describe how you can make use of the same alternators you've already purchased.

After some research, I discovered that most single-wire (self exciting) alternators need well over a thousand RPMs to start producing current. Your tractors are lucky to produce a few hundred RPM when you rev them up. This is not good for a cold engine or even a warm one, for that matter, IMHO.

So, I did some research and discovered that you can use your current alternator with the addition of a few inexpensive parts to make it a three-wire alternator that will begin charging the moment you turn on your tractor. There are kits for this, or you can simply take your alternator to a local repair shop, like I did, and have it done for just a few bucks (probably much less expensive than trashing yours and buying another, at least).

If you'd like the links to the information I found on the Net, just drop me an email and I'll be happy to send them over to you in a return email. A Google search should produce the same information for you, however. I'd suggest just checking your local 'Yellow Pages' and finding a good alternator repair shop, however. The labor rate on this work is minimal.

I don't know why my email is not open. I just checked and it is supposed to be available. At any rate, here it is:

hevans AT his DOT com

(please remove the spaces and use the symbols instead of the words in CAPS)

Using a small pulley will give the alternator well over 1000 rpm's. That is the alternator rpm not the engine RPM.
When saying you need over a 1000 rpm's {On The Alternator} that is not the engine rpm's. The engine rpm's will be much lower.
There are many reworked sigle wire alternators on the market that excite at very low {Alternator} rpm's.

I discovered that my alternator required about 1800 RPMs to self excite. My Farmall H can't even come close to that, even with different pulleys. So, I solved the problem another way. I'm sure each alternator brand is different from mine, but I wanted to show a solution that WILL work on all alternators, if need be.

I DO NOT like one-wire alternators, but surely your "H" runs at lease 1100 RPM's with a crank pulley of at least 5" diameter, meaning an alternator speed of at least 2750 RPM's, which should be enough to excite ANY alternator worth having.

I have many single wire alternators of different brands on tractors that have around 800 to 1000 engine rpm"s and I have never had one not get enough rpm"s to get it exited.
I use the 2 1/2 inch pulley.

WHY NOT just get a good salvage yard 10SI already made to be hooked up 3-wire and save the money AND aggravation of returning a BUTCHERED alternator to it's original configuration?

The one-wire 10SI's or simply NOTHING but an aftermarket butchered abomination.

Anybody who can't follow one of the 2 simple picture diagrams I posted as to how to connect a Delco alternator up so it WORKS should stay away from electrical systems!

I have many single wire alternators of different brands on tractors that have around 800 to 1000 engine rpm's and I have never had one not get enough alternator rpm's to get them to excite.
I use the 2 1/2 inch pulley.

You're right. This probably would have worked. However, I don't like revving my old tractor that high -- especially when it's not warmed up yet. So, I chose a different route and now my alternator has an 'excitement' charge coming from the battery, as do other three-wire alternators, and it begins to work from the first moment I start the tractor, no matter how slowly it's turning over.

Thanks for the information, though. I might just use this technique on a future tractor or other vehicle.

I DID NOT purchase the original one-wire alternator and really didn't want to abandon it because it DOES fit under the hood of my Farmall H. Most other alternators are a bit too big for that spot, according to the guy who recommended this alternator for my tractor. It was a pain to diagnose and rectify the problem caused by this bad choice of equipment. However, the whole mess did prompt me to do some research and I ended up learning quite a bit about alternators. Without any of this, I'd still be in the dark, so I'm grateful -- .... and my tractor is charging its battery for the first time in many months, ... so I'm happy with the end result. I'm simply offering some advice on a different solution such that others can learn, too.

We all have to go through some experiences in order to understand and master any complicated subject. I didn't learn how to become a concert violinist or a master violin maker over night, either. Now I wish to learn about antique tractors, so I'm grateful for experiences that teach me the ins and outs of these marvelous old machines.

Thanks for being here to answer questions from beginners like myself.

Thanks for the input. Why the idiot light?

The experts here will either confirm or correct this information, but from what I have learned the 'idiot' light serves a similar function as that of the diode. That is, it keeps the tractor from running on after you turn it off and also prevents the battery from draining down while the tractor is not running.

Do a Google search for alternator and diode and you will find lots of information on this subject.

Looking at the two excellent pictures in this thread of the alternators and how they should be wired, you can see that both have very similar wiring schemes. The wires with the light and the diode are the same and go to the same places. I think they are interchangeable. Again, the tractor experts will correct me if I'm wrong.

(I'm off now to double check on this myself, with the help of dear Miss Google)

(quoted from post at 17:16:58 08/08/10) WHY NOT just get a good salvage yard 10SI already made to be hooked up 3-wire and save the money AND aggravation of returning a BUTCHERED alternator to it's original configuration?

The one-wire 10SI's or simply NOTHING but an aftermarket butchered abomination.

Anybody who can't follow one of the 2 simple picture diagrams I posted as to how to connect a Delco alternator up so it WORKS should stay away from electrical systems!

Click to expand...

Bob, why don't you tell us how you really feel about those self exciting alternators? :wink: :wink:

Actually a self exciting alternator does not have to be aftermarket. You could get them Delco and are very common in larger alternators. When used on trucks and buses with multiple batteries the drain is much less noticeable.

In most cases with the 10SI series alternators the only difference is the regulator.