Alternator or Generator

[Swanybawanie]

The previous owner of the 440ic had an old alternator on it with one wire and some silicone over the hole where the other wire was supposed to be, is this the one wire alternator system I read about? There’s no battery in it so no telling what voltage it was, I would like to go to the older way with 6 volts, I came across someone selling 6 volt alternators, you have a choice of:
1. Negative
2. Positive
3. One wire

What would you do?

[gregjo1948]

I'd go with the 6 volt using a positive ground. I think that' what it would have been originally. You'll need a voltage regulator also.

[Stan Disbrow]

Hi,

I'm into keeping a 6v system at 6v, unless one changes the starter over as well. 6v is positive gnd, 12v is negative gnd.

Note that Lavoy has the 12v stuff including starters. And, the 6v stuff as well.

Stan

[Jim B]

Sounds like someone lost the rubber plug normally installed over the two terminals inside the alternator and filled the hole with silicone. From your description of it having an alternator on it now; I believe it was being run 12 volt, negative ground. Some other clues can be: size of the battery cable battery clamps, positive clamp will be the larger one as battery positive posts are larger than negative posts. Does that cable go to ground or to the starter. Are the primary terminals on the coil marked? If done properly on a negative ground system the wire to the distributor will be on the coil primary - terminal. Is there a ballast resistor wired into the wire from the switch, ahead of the coil?

I would either go completely back to the original 6 volt generator, positive ground system or I would go 12 volts, negative ground, with alternator. I would not go to a 6 volt alternator of either ground, which I believe would have limited sources for replacement if needed later on. If going to 12 volt I would get with Lavoy for a starter upgrade to 12 volt (If you return to 6 volt, I would expect your current starter needs an overhaul anyway since it sounds like it has been being used with 12 volts.) If upgrading your current alternator, I would stay with the Delco 10/12 SI. I would consider the three wire Delco or one of the one wire types set up to start charging at lower rpms. If I wanted a smaller physical case size I look at one of the small case Denso types or Hitachi types. The alternator should have a smaller pulley with the right belt width, not necessarily the one that comes on an alternator. Reasons I'd go this way are: 6 volt batteries can be harder to find a good fresh one (more 12 volt options and stock turn over is usually better), parts (Internal regulated alternators) are easier to find if there is a failure, and while I believe Delco generators are good, there are many reports of people having a good bit of issues finding good quality, long lasting, regulators for them. My thoughts for what their worth.

In any case, you should check to see that the coil is correct (or if a ballast resistor is needed) for which ever voltage and polarity you decide on. Ignition cap, rotor, points, and condenser will stay the same either voltage. Don't fall into the 12 volt distributor cap trap. A cap doesn't know voltage, there are different two cylinder caps for Dubuque built two cylinder tractors (your 440IC) and Waterloo built two cylinder tractors. As has been discussed here before, the posts are located differently in the caps and are not interchangeable. And of course light bulbs must match the voltage you chose.

Any of the ways will work fine if done properly and completely, the choice is yours.

[Lavoy]

I would go back to completely stock, or 12 negative ground alternator conversion, 10SI or Denso. I have mounting kits available for the 10SI, bolts right on. The Denso is smaller, might fit under the hood better, that is what I have on mine.
Lavoy

[Paul Buhler]

I’m in the go with the original system group. Over time I’ve rebuilt my whole 6v positive ground electrical system, and it works reliably. The starter cranks well, and the dozer fires up usually on the initial spins. I did go with a bigger battery cable to reduce resistance while cranking.

[420C-Mike]

I agree. 6 volt system works good with heavy cables and a good battery. Same was true of my 1950 Studebaker pickup with 6 volt system. Only time it didn't start was when I pushed the clutch pedal to the floor to engage the starter button and it kept cranking until I realized the key was still in my hand and not in the ignition- oops!!

[Stan Disbrow]

Hi,

Both my 1950 M and 1958 420c are all original 6v. They always start right up. All my other old 6v iron was original save one 420w which arrived with 12v. It didn't stay that way long. I can't stand the screaming from a 6v starter on 12v.

Stan

[fundytides]

Another vote for 6v original. My 40c had been converted to 12v when I got it and had a broken nose cone on the starter. I found a used nose cone and generator and went back to 6v. Never a problem even after motor was rebuilt and a little stiff. Usually starts on 1st or 2nd turn. My son-in-law has an original MT still using 6v and it will start quickly even though it has a sticky valve and usually fires up on one cylinder and then the other one cuts in. These machines were designed to start reliably on 6v and normally do so. I have some antique cars as well with 6v systems and have not had any problems with starting. The Model T was designed to start on the hand crank so the starter on mine is a bonus. Just have to make sure to retard the spark when starting so kickback doesn't break the Bendix spring, or your arm if you are using the crank.

[Stan Disbrow]

Hi,

Oh, yes. Thanks for the reminder. I'd forgotten about that. My M and 420c can be hand cranked. Comes in handy sometimes.

Stan

[Lavoy]

I would add that my 440 is on 12 volts, and I will be rebuilding the starter to 12 volts. For me, sooner or later I am going to be forced to start it well below zero in the middle of a blizzard to move snow, or dig the groomer out of a ditch some place, so I need the reliability of the 12 volts for an emergency situation where I did not have the block heater plugged in. I also have LED headlights and a large Halogen tail light to work at night. Other than that, I am and have always been a fan of original. I am also quite opposed to 12 volts without converting the starter as well.
Lavoy

[Swanybawanie]

I checked the battery cables and the black has been grounded and the red cable is bigger, the previous owner said the last time he started the dozer the starter “exploded”. Right there proves the 6 volt starter couldn’t handle the 12 volt, it has a broken ear off one of the bolt holes, plan on having:
1. the starter rebuilt,
2. the wiring corrected ( need to find a better diagram)
3. The head redone
4. The engine rebored w new sleeves
5. Crankshaft re-ground

[Swanybawanie]

Mr. Lavoy, I have a reputable mechanic that has done the head work on the 440IC the gentleman has advised me to stay with the 12 volts and have the 6 volt starter rebuilt To 12 volts, I might go that way, do you have a 12 volt diagram conversion?

[Stan Disbrow]

Hi,

Wiring is easy since the battery cable goes to the starter. Get a 12v one. Get a one-wire alternator. Run that wire to the starter. Run a wire from the battery to a toggle switch, then from the switch thru a resistor to the 6v coil. Or replace 6v coil with a 12v one. Then from coil to points. Done. It'll start, run and shut off via the toggle switch and the starter pull rod.

Lights, run another wire from the battery to another toggle switch then wires from switch to lights.

The factory wiring only makes sense with the original 6v system as you now have an outboard mechanical voltage regulator and cut out relay and field windings to deal with. More wires.

You can get a new ILDB switch if you don't want to use toggle switches. Just ignore the D position or run a wire from that to a separate tail lamp.

Stan

[Swanybawanie]

With a 12 volt system will the 12 volt starter run normal like a 6 volt starter with a 6 volt system?