Is my charging system working?

I have a 1952 TO-20 with a 6 volt generating system. I need to know how I know is charging. I just installed a rebuilt generator, new voltage regulator and new ammeter and finally got the tractor to start. The ammeter deflected initially back and forth to the positive side for a short time and then settled to zero. I used the tractor for about 3 hours with no movement on the ammeter. I rechecked all wiring and will tighten the fan belt a little this morning but it was already quite tight. Questions:
1. How much should the ammeter deflect when charging? My old system went to about 15 amps, I think.
2. How can I test the new components? I have a multimeter and very basic knowledge of things but can follow instruction
well!
3. If it ain't broke I guess I don't need to fix it. Just want to understand better what I am or am not seeing.

Thanks in advance for any help you can give.

one word...polarize. more and BETTER answers will follow.

After starting you should see meter hand show charging. After running it should go back toward the 0-5. This shows it charged the battery. Another way to check generator is to start tractor and then remove positive cable. If engine still runs it's working. If engine dies then it's not working. It will run(electrical) from the generator and not the battery. From what you say it's working.

Remove positive cable even if tractor is positive ground?

I know how to do that and will do so. Thanks for the suggestion.

not a fan of removing a cable while machine is running to check charging system!~! can damage components. check battery voltage with engine off with meter, then start machine and check it again, if working, voltage should go up , depending what state the battery is, maybe up as far as 7.5 volts. first polarize the regulator.

If you didn't polarize the generator, it isn't working properly. That should have been done before starting it, but I would go ahead and give it a try.

When charging properly, you will see the amp meter swing to the + side momentarily when the engine starts and the RPM is brought up above the threshold charging voltage. Depending on the level of charge left in the battery after starting, the generator will replace the charge as needed. The more discharged the battery, the longer it will need to charge. Once back up to charge, the regulator will slowly bring the ampmeter down to, or close to the center, but not let it fall to the discharge side.

If the lights or an accessory are turned on, you should see the needle jump slightly then return to the center. If the engine is brought to a slow idle and the accessory's are still on, the needle will fall to the - side.

What you don't want to see is the meter falling below center to the - side with the engine RPM up off idle, indicating lack of charge, or see the needle stay over on the + side for an extended period of time, indicating over charge.

A simple test is to place the multimeter across the battery. Start and run the engine above the threshold RPM (1000 or above). If the battery is close to or fully charged, the volts should read around 7 to 7 1/2 volts. If the battery is low, you should see the volt meter slowly come up as the battery is being charged, then level off to 7 to 7 1/2 volts.

Be careful running the belt too tight. The old generators had bushings, not bearings. They don't need, or like tight belts!
Polarizing a Generator

I read the instructions and I have but one question. which is the "A" terminal on the generator?

Steve, the terminals should be marked.

One will be the F (field), the other is A (armature).

You can also trace the wires back to the regulator. Spark the B (battery) terminal to the A or G terminal, however it it labeled.

Steve--Very thorough and helpful answer. I have polarized the generator and the ammeter needle did deflect today at starting. Nothing in the negative side. I will test with multimeter tomorrow. I don't have any lights or accessories on this old TO-20 to test in that way. Thanks for your help.