M - converted 12V, need wiring advice

Been working on an M that has been parked for about 30 years in a shed. Engine isn't frozen, and I've replaced the belts, changed the oil, spark plugs, spark plug wires. A lot of the electrical was in disarray, and I am not sure how to re-wire everything up again. The coil was missing, so I replaced it with a 12V w/ internal resistance, so I wouldn't have to use a ballast resistor, as shown in the link. Is this correct? I used a Tisco 396547R93.

For the most part, I have deciphered the wiring up until it wires into the alternator and the coil. This is where my confusion begin. Alternator has a "BAT" terminal, then one port with "R" & "F" on either side. Only one wire coming out of it. Also, it looks like there was a voltage regulator on it, which I have removed (temporarily), but I have shown its orientation in the pics.

To help clarify the pics, the green wire goes to the on/off switch that you have to pull out before the starter will work. Blue & yellow wires go up into the ammeter and light switch housing. Yellow wire is cut up near the alternator when all three wires come out of the sheathing. A red wire seems to be spliced into the green wire before the voltage regulator(?), and the green wire was hanging loose. Based on the drawing in the link, I think it goes to the "+" terminal on the coil. The alternator has a "BAT" terminal, but no "1" or "2". The dual plug is an "R" & "F".

I can't quite make sense of what I need to do now, and/or where to find the wires I need to connect to the "-" coil and the wires that are missing for the alternator. Any help is appreciated.
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Your alternator is a Delco "10DN" which requires an EXTERNAL regulator, and the diagram you are looking at shows a Delco "10SI" alternator which has an INTERNAL regulator.

The regulator in your photo is not the typical one I would expect to see with a 10DN, it may be an older version I am not immediately familiar with, or the alternator/regulator combo may be something that has been cobbled together.

Also, do not worry about the lack of a connection to the "R" terminal. That is NORMAL.

All that being said, your best bet may be to pick up a good used or rebuilt 10SI alternator, then follow the wiring diagram you have.

You can probably find a good one at a boneyard for $10 to $20, or get a rebuilt for $60 or less.

Ask for an alternator for a 1976 Chevy pickup with NO air or power ANYTHING.

Providing the regulator is working all you need to do is connect the field wire from the regulator to the F terminal on the alternator. The other terminal on the regulator need to be connected to a switched power source, most likely the ignition switch. The regulator base must also have a good ground.

The system should work that way but it certainly is not the best way. In this case all the power to energize the field coil (rotor) in the alternator has to come through the ignition switch. As long as you are not placing any great demands on the charging system it should work OK for you.

A Delco style regulator for that alternator would normally have four terminals. One terminal would come from the ignition switch, one from the battery, one from the R terminal on the alternator, and the other connecting the field. wired like that the power from the ignition switch would be used to first get the alternator to begin to charge. Once it had started to charge the R (relay) terminal would provide power back to the field relay in the voltage regulator which when closed would connect the wire from the battery to the voltage relay so that further power needed to energize the field coil would no longer have to come through the ignition switch. A second use of the R terminal is to control an indicator light.

If that says IGN and FLD on the box, that's an old Dodge cutout, used to prevent the backflow of electricity to the coil. It should go between the switched side of the coil to IGN (red spliced wire) and blue wire on the alt to FLD. Dads was setup that way.

Ok, not to derail the subject but did you purchase this tractor or did it set in your shed 30 years? Are you aware if it even run before it was parked? Finessing all the wiring is fine but I myself would like to know engine condition before I got into anything to deep. A jumper wire to the pos terminal of the coil, good points in the dust. and jumper cable to the starter terminal is all you need for a test run. If the fuel system is up to pare you should be good to go. Please make sure it is in neutral before you attempt any of these short cuts.

It was my grandfathers, and he parked it in a shed in the mid-80's when he bought a JD 4020. It was running at the time, but he apparently cannibalized some of the electrical parts for his H, which is why I am trying to decipher how to hook it back up. It was also converted to propane, and I am currently rebuilding the Century Regulator.

I'll see if I can find a 10SI, it may be simplest (and better) to just switch it to that configuration.

Replacing the existing alternator with a 10SI is the simplest (also the lowest cost....) fix.

Incidentally the box with the IGN and FLD markings is an alternator voltage regulator from a 60's era Chrysler product. So your charging system is truly "cobbed" together. It could PROBABLY be made to work with your Delco 10DN but I would not recommend it.

If I was to pick up a 10SI, what amp rating would I need? And clock position? Ran across this article (link below), and want to make sure I get the right part.
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Those old Chrysler regulators would make any alt work if it needed an external regulator.

The least powerful is just fine. (35 amps IIRC) There is no clock position that matters, the mounts are part of the front frame. Jim

go to your favorite auto parts store and ask for an alternator for a '78 1/2 ton chevy pickup.

Any amp output rating is fine. 55 amp is most common. However a lower rating of 42, 37, etc is preferred for a tractor with modest electrical requirements (the lower the amp rating, the lower the RPM required for the alternator to begin charging)

Clock position of the 10SI rear cover relative to the mounting ears is easily changed in 90 deg increments. Simply remove the 4 long screws holding the alternator together and pull the rear cover off. Use a piece of stiff wire inserted thru the brush holder to temporarily hold the brushes back. Then put the rear cover back on in the new clock orientation, replace the screws and finally pull the temporary wire out of the brush holder.

I dont know the condition of your old 10DN Delco alternator and 60-69 Chrysler regulator, but be aware, that what you have is every bit as reliable and easy to wire as converting to a 10SI Delco.

What you have, is to simply mount that Chrysler regulator in a location that is well grounded, connect switched 12V from the ignition switch to the regulator IGN terminal, connect the regulators F terminal to the F terminal of the alternator. Connect the alternators output(BAT)terminal to the ammeter post that has multiple wires, as the post with a single wire must be connected to the battery only.
Thats all there is to it, that simple little 2 wire Chrysler regulator will do a good job of accuratly regulating most any external regulator alternator from Ford / Motorcraft, GM / Delco, or chrysler.
Determine the condition of what you have and go from there.