Generator

1 - May be the battery is fully charged and the regulator is simply doing it's job. If a voltmeter is placed across the two battery posts and it indicates 7.2 volts or higher while the ammeter shows 10 amps, there is no problem!

2 - High resistance in the wiring between the generator "A" terminal and the battery. Use an accurate DC voltmeter and take a voltage drop measurement between the generator "A" terminal and the ungrounded battery post with the engine running at full RPM. A reading greater than about 1/4 volt says there's excessive resistance in the circuit. Look for bad connections, undersized wiring, etc.

3 - 3rd brush set to low. Readjust it to it's maximum current position - so 3 commutator bars are showing between the 3rd brush and the nearest fixed brush. Keep in mind most 3 brush tractor generators are only designed for about 14 amps max output. Higher output can cause overheating and damage.

4 - The armature has one or more shorted or open windings. If the generator gets hot to the touch after running about 15 minutes, or if the enamel insulation on the armature windings appears baked/burned, the armature has an internal short. An open winding can be found by probing the commutator with an ohmmeter. Either condition requires rewinding or replacing the armature.

5 - (long shot...) Could be a high resistance ground at the regulator.

Note to Pappy - 6 volt IHC tractors built after about 1949 or 1950 use a 3 brush generator with a 2 element voltage regulator in place of a cutout. Pretty sure other tractor builders using Delco electrics did the same.

We've got three '53 Farmall "Supers" with the original Delco generators. Two of them have an adjustable 3rd brush generator; the other does not.