Parts & Stuff => Product and Accessory Forum => : Log Skidder October 28, 2003, 07:52:35 AM

: generator vs. alternator
: Log Skidder October 28, 2003, 07:52:35 AM
I have an HG-68 with a hercules IXK3 engine.  It had an Autolite generator on it.  Well, I did a little work on the engine I fired it up and after a while the fan belt started disintegrating.  

Note:  it is not good to be sitting on the front, right support tinkering with the throttle and magneto as you are showered with large chunks of melting/burning rubber.  At least you are near the kill switch on the magneto.  

Turns out my generator was siezed up.  It might have been the whole time, even when I was cranking the engine by hand to do valve work, etc.  The belt was probably worn enough to slip by.  I tore the generator apart and it looks like a lot of water has gotten in and rusted up the rotor laminations right to the outside field.  Maybe a Kano Labratories product called Ex-Rust might cut through it, but I don't know what that might do to the copper wire or the wire insulation.  

Zimmerman's didn't have a core for the Autolite.  He said I could buy the whole shebang for a Delco Remy generator, but I would like to upgrade to a 12volt system over the 6 volt generators.  I jump start the thing with my truck anyway.  When I bought the crawler it had an 8 volt battery, which is difficult to charge if your AC battery charger charges at 6 or 12 volts and the generator on the engine is for 6 volt.  

So Zimmerman recommended that I buy a single wire alternator ($75) and build a bracket to fit it.  Anyone ever do this, or have recommendations on how I should do it.  I shouldn't have too much trouble welding up a bracket, but I would like to use 3 points to secure it instead of the 2 that the generator used.  

I think I will have to switch it over to a negative ground system for the alternator to work right.  I noticed that the starter works right which ever way you run the current.  I guess that has to do with the fact that it is a series wound DC motor versus a permanent magnet motor.    

Thanks for any help you can offer.

: Log Skidder October 28, 2003, 08:15:34 AM
I was just thinking, whoever has switched to an alternator, do you have any problems with the engine having to be at high RPM's, well high in this case is 1700 RPM, before the alternator starts making current?  Or are the differences in pulley diameters enough to get the alternator up to speed?  Anybody have a model number or a part number for an alternator they used?  Thanks.

: Blake Malkamaki October 28, 2003, 12:20:19 PM
It all depends whether you want your tractor to be all original or you just want to work it.

The 12 volt alternator should be an easy project. I did that to my Farmal Super M. You need to switch it over to negative ground, which is no problem. You may have hood clearance problems. Please don't cut the hood to make it fit! As far as RPMs, you may have to rev it up to get it to start charging, but it will keep charging at idle after that.

If you do convert something with a distributor ignition, you'll need to reverse the polarity on the coil and install a ballast resister in the line to the coil.

If you are restoring your  tractor and want to keep it original, I would stick with the generator. You can still go to 12 volt. Generators should be easy to find. Check with a local generator/starter shop. I just sold a nice 12 volt generator off a Jeep that would have worked.

Good luck.

: Log Skidder October 28, 2003, 02:19:14 PM
I like the physical performance of a restoration more than cosmetic.  I rebuild things to restore power and improve reliability.  I would rather fix things when they are in the shop than out in the woods.  

I don't think I would be really keeping it authentic if I went with a 12 volt generator or alternator.  It came with a 6 volt.  

Blake, when you say the 12 volt generator would work, do you think it would fit in the same bracket/clamp as the 6 volt one?  If I have to fabricate a bracket for the 12V generator then I think I would be better off with an alternator, something that I can buy off the shelf anywhere, cheap.  

I would make a cosmetically appealing bracket, because what I would term a junky one would have poor welds, etc.  somehow I like the alternator better than the generator.  I don't know anything specific that says that one is better than the other, but I am used to working with them.  

I did a search on alternators on this site and it seems someone used a GM ST-12 alternator.  It seems that a lot of hot-rodders, automotive people, and even a couple old tractor sites use a lot of Delco 10SI one wire alternators.  Some of these alternators also have a three wire setup so that you can hook your battery to two of them (one BATT, the other for the field) and then the third one is for a light to indicate when the thing isn't charging.  Anybody use one of these.  I see on ebay there is a replacement rectifier that you can buy so that the alternator "turns-on" at lower RPM.  

Say, any idea why you have to rev it up to get it to work and then you say it will charge after that at any rpm?  I see some of these alternators are self exciting.  Then there are some like the three terminal type.  I have been reading that usually you use a resistor in series with the field terminal and positive on the battery.   But vaguely I am remembering something that an old mechanic told me that you could do away the resistor so that the alternator would start generating current at a lower RPM, but you have to be careful on car applications because if you do that at high RPM's you could burn out the regulator.  That just might work for me here.

: Log Skidder October 28, 2003, 02:24:49 PM
just one more thing.  I think if I went with a one-wire type that hooks to a BATT post on the alternator you don't have to worry about discharging the battery when the engine is off.  But if you use a three terminal type you have to add a switch to turn on power to the "field" terminal, you get around the "high rev to start charging" issue by supply battery power to excite the field, but you need a switch when the engine is off otherwise the "field" will discharge your battery.

: Blake Malkamaki October 28, 2003, 03:03:21 PM
My experience with the one wire alternator is with the Delco I put on the Farmall. It takes some higher rpm to get it charging, but it will continue to charge at any rpm thereafter.

It's your choice on the alternator/generator decision. It's all in what you want. I know alternators are what many of us are used to working with, but generators are still prevelent and obtainable. You can probably even have yours rebuilt by a local shop. Or you could exchange it for a 12 volt one. You'll probably be able to find one with the same housing yours has that will bolt right in.

: Log Skidder October 28, 2003, 03:26:18 PM
I like that idea of bolting one right in.  I will measure up the housing and start looking for one.  There is an electric motor repair place near me that has helped me rebuild starters and motors before.  The one I have is pretty well rusted into the housing.  I wonder what that rust does to the laminations.   Maybe if they can get that one apart they could convert that one to 12 volt.  

I don't know the accuracy of this next statement, but I remember my dad saying once that a generator will always put out a voltage higher than the battery, this is of course if you don't have the little regulator box that basically switches off the generator when the voltage gets to a certain potential.  If you could change the set point of the regulator you could make a "6 volt" generator charge a 8 or 12 volt battery.  But you need the regulator to prevent overcharging.

: Log Skidder October 28, 2003, 03:36:03 PM
but then there is the easy-to-find, easy-to-fix alternator.

Argh.. the inner struggle of a gemini.  and an engineer to boot.  What did they say when we graduated, "you all have just enough knowledge to be dangerous."  

I think my crawler is possessed and it is trying to kill me.  First the magneto tried to do it.  Then it threw melting rubber fan belt at me.  Makes me think about the big tank of gas between me and the engine.  If anything ever caught on fire there is that nice big cooling fan to blow it my way...   :D:D:D

: Charged up
: ggibby October 29, 2003, 12:32:49 AM
If you find a orignal generator then you could add a 12volt cut out.
The field could be changed on it to make is neg ground if you like too.
The St-12 on my HG is big 65 amps max, way more than it needs.
but it was what was a the junk yard, 25 bucks if I'm remembering correctly.
I made a "F" shaped bracket that mounts to the outside of the oil filter adapter on the engine with longer bolts for the bottom bracket.
And a non-adjustible strut for the top, I use the fan pulley adjustment for belt tension.
I used the smallest pulley I could find and a Green lawn mower type belt.
The GM altenator can be adjusted to come on sooner, a professional thing no doubt, I didn't bother.
Self exiting alt's are fine, I used a three wire type and used the back light for the alt gauge for the load, It works fine.
The ST-10 is a smaller than the 12 but there is no reason why a "import " or some other alt. from a sub-compact car would not work.
You no doubt know you will not be able to run your 6 volt lights, I like the 10 dollar Walmart utility lights 55watts brite each!
This a good way to make your tractor more relible, Hmm no more jumper cables.
Good luck.
George Gibby

: Log Skidder October 29, 2003, 07:07:31 AM
Thanks G Gibby.  Good information.

My crawler didn't come with lights so I have added the $10 ones you mention.  Napa has a huge bin of them.  They worked all right off from teh 8 volt battery.  Enough to get me out of the woods without driving into a ravine or into a tree.  

They will probably be amazingly bright once I get everything set up for 12 volts.

: Log Skidder October 29, 2003, 07:11:37 AM
To G Gibby, do you have an amp gauge or anything to see what the alt is actually putting out?  You say that you used the smallest pulley you could find, how big is it, roughly? or did it come with the alternator?  

The green lawn mower belts, are you talking about the kevlar fabric wrapped ones they use for belt drives that are engaged/disengaged?

: Log Skidder October 29, 2003, 08:54:17 AM
Hey everybody I just found out a great place for information about Delco 10SI and 12SI alternators.  Also there is an article about the differences between one-wire and three-wire alternators.  

go to (

: Log Skidder October 29, 2003, 02:43:59 PM
I have been studying the information on the ( about the Delco SI series of alternators.  

First let me say that that site is mostly for retrofitting these alternators into muscle cars.  

The Delco 10SI and 12SI was the standard model in Chevy Vehicles for quite a while.  

I guess now the new series is the CS models.  The 10SI and the 12SI are cheap too.  The 10SI I have seen for 16.99 at (  They have a one-wire 10SI for 24.99.  

To Clarify my earlier emails, the difference between the 1 wire and 3 wire is that with the three wire you get a warning light connection and a voltage-sensing connection.  For our battery-charging only applications, you don't really need the extra two connections.  However for 8 dollars cheaper you can get the 3 wire and simply connect the voltage sense conncetion "F" to the Batt terminal on the alternator and everything is fine.  And the alternator will work fine without anything connected to the warning light "R" connection.  When dealing with a car situation with long wiring harnesses you can connect the voltage sense connection to wherever you want the alternator to produce 14 volt potential.  

This remote voltage sensing connector gets you away from having to rev the engine up before it starts to produce power.  The one-wire has to charge itself to turn-on it's regulator before it can start producing charging current to your battery.  

Anyway, the website says it better than I can.

: Log Skidder October 29, 2003, 02:46:05 PM
Oh and I found out the 10SI and the 12SI have the same case as the externally regulated Delco 10DN.  I have one of those on my Case Backhoe and it also has been in need of repair.  So I am going to upgrade to the internally regulated one.

: pvcarey October 29, 2003, 10:05:18 PM
 On my 8n ford I used a datson alt. it had a 2 piece pulley, I put some washers in-between to make it fit the wider belt, it had to have an external reg. I used an older dodge reg. for that, the alt was small, had the 3 point mount, and I liked the pulley set up. (and had all the parts in my junk) I have a generater on my hg but it dont' work I just put it on the charger when it gets low with no lights it lasts a long time. Ron

: Log Skidder October 30, 2003, 12:13:27 PM
When I first bought my HG the battery had been swapped for an 8 volt, so I don't know if it would have worked, but at least it spun freely and allowed the proper belt. But now it is seized up and that doesn't work at all.  My habit of leaving the charger on it overnight may have not been good for the battery either.  Sometimes I would forget about the thing charging.  I suppose the best thing is to have a good alternator for charging when you're running it and then one of those battery maintance boxes that you can plug in to an AC source when you are not using it (like over winter).  Compare the cost to buying a new battery each spring because the old one discharged, then froze and cracked the case.

: Blake Malkamaki October 30, 2003, 12:31:46 PM
I moved this thread over to Product and Accessory as it could pertain to any model and is more accessory related than tractor. A good discussion though.

I'd like to see some imput on repair places and suppliers that will repair or sell replacement generators for these tractors. This I will add to the site under "Parts Sources".

: Charged up
: ggibby October 30, 2003, 10:21:46 PM
The Green Belt was supposed to be for low horse power applications.
I think that running lawn mower blades and the like was the real intent for it.
But I figured that 5 hp for the fan/water pump and 5hp for the alt. and that low rpm in general of the tractor that it would be fine.
And I think that the green one fit or was availible at the time.
The pulley is a 2 incher that was on the junk shelf the old one was a 2.5 that came with it.
I was just trying to spin up the alt to charge more at a lower tractor rpm.
I used an after market Amp. gauge to replace the broken original, a Volt gauge my be easier to judge battery state though.
Having a more relible machine tents to melt away the original vs. mordern ease less of a debate for the owner.
Do the best job of the updates you can and you will be happy with a job well done.
Good luck.
George Gibby

: Log Skidder November 03, 2003, 09:46:28 AM
Well I think I have the three wire thing figured out.  

I replaced the alternator on the Case Backhoe over the weekend.  It turned out that it was an externally regulated Prestolite alternator, but the Delco 10SI was a perfect fit, both the belt pulley and the mounting locations were a good match.  

So with a three wire, you have the Batt terminal, and  then a connector for the other two wires.  Some of the end cases are labeled with "1" and "2".  There are plenty of sites that show illustrations.  

The number "2" wire is the voltage sense wire.  Wherever that wire is connected, the regulator will adjust the alternator to gring that point up to 14.2 volts.  I just hooked mine to the "batt" terminal on the alternator.  So with everything running the batt terminal was at 14.2 volts.  And due to current flowing to the battery and the resistance in the cables going to the battery, I measured 14.12 at the battery.  perfect for charging.  If I wanted 14.2 volts at the battery I could have hooked the number two wire to the battery terminal.  Then the output from the alternator might have been 14.5 or something so that the battery lug was at 14.2 volts.  

Then the "1" wire is the "turn-on and warning light terminal"  This does not have to be connected to anything.  But it can be connected to a ignition switched source as well as a warning light.  The way this is wired is that you connect from the positive battery post a switch (ignition "on") then in series a warning light and then to the "1" wire connector on the alternator.

When you first turn on this switch, without engine running, the regulator "1" terminal is low so the light will be on.  power flowing through the light also "turns on" the regulator.  This means that you don't have to rev the engine to "self-excite" the regulator.  It starts working at 500 RPM.  When you get to 500 RPM the warning light should go out because the "1" connector is brought up to the output voltage of the battery.  If you broke a belt or the engine stopped (of course you would be aware of these things on a tractor) the warning light would come on again.  

Cool stuff.

I agree that reliability is the best of all.  

And of course this high-tech alternator can be had for $25-$30 from any auto-parts store, even cheaper online ($16) compared to $200 for an authentic generator and regulator.    I can build a pretty fancy bracket and a special pulley for the wide belt for a lot less than $170.  

Would anyone be interested in buy a bracket and pulley for this type of alternator for their IX series engine?

: QAlternator
: John Schwiebert November 03, 2003, 08:47:14 PM
A couple other things and I am not in the thinking mode today. Had to go to doctor should be over that in a couple of days, anyhow the 6 volt lights will get real bright on 12 volt and then it will get real dark. We just took alternators from the Junk yard and hooked them up. If I remember correctly we put a resistor in the one wire. The single wire setup came later and I think it is the way to go. We did a bunch of 77 & 88 diesels and never had any problems charging at low speed. I guess this winter I need to research some of this stuff. Have not done it on a regular basis since 76

: Alternator
: Log Skidder March 16, 2004, 10:26:21 AM
I am almost finished with the alternator bracket.  

I am switching things around a bit on my crawler, so many things have been modified on this machine by previous owner(s) that I am not concerned with restoring to perfect original condition.  

I am adding an ignition switch, one with a key, that has four positions, off, accessories on, accessories and ignition on, and momentary starter.  I am going to run a 12 volt battery, 12 volt alternator, a switch for lights (previously I had no lights at all so this is an improvement).  Also there will be a starter solenoid activated by the ignition switch.  I am going to run another relay to work with the ignition.  basically I am using a normally closed relay hooked up to the magneto.  So that when the relay is not energized the magneto wire will be pulled to ground.  When the ignition is turned on the relay activates and pulls the magneto wire off ground.  

I think I might relocate the battery up front.  I was going to add a bracket to put weight up on the front of the machine anyway to help keep the front end on the ground when I am pulling logs.  And that gets the battery away from the area between the gas tank and brake levers.
That will make it easier to get to the battery If I have to jump start something.  

I will try to send some pictures of the alternator bracket when I am done.

: Bill Seal March 18, 2004, 10:27:14 PM
Nobody asked, but I have been running my OC3 starter on a 12 volt battery for 25 years or so, and the one on my Ford V8-60 powered hot rod for about 50 years. They just spin REAL fast! The rod has a Mazda alternator, but the OC3 just runs on the battery (magneto, no lights). Wal Mart has a cheap 10 amp marine charger which just cuts out when the batt is fully charged, and won't over charge it.

: Blake Malkamaki March 18, 2004, 11:21:46 PM
Running 12 volts through a 6 volt starter is probably better on the starter than running 6 volts as they spin so fast and start so quick. Therefore the starter is not used as long.

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