In Reply to: Ford 600 generator posted by Jon Calder on November 18, 2019 at 10:53:42:
The correct generator for a 600/800 is the 3-Wire/2-Brush B-Circuit Designed 20 AMP output style. "G" is always GROUND. "F" is always FIELD, and "A" is ARMATURE. Voltage Regulators are sometimes marked with a "G" for ARMATURE -same thing, but most will say "A". Polarizing the generator should be done when installing new components. It is important to know which circuit you have. OEM Ford Tractor used the "B" Circuit with eth original OEM early 9N small 2-Wire/2-Brush generator and VR. All other N's used the "A" circuit designed generator starting with the s/n 9N-12500, 1-Wire/3-Brush unit and cutout til 8N production, using the 3-Wire/3-Brush unit with a VR, and later 3-Wire/2-Brush unit. The NAA model began using the "B" Circuit design again thru Hundred Series and beyond. If you jumper the wrong way, you will surely fry your VR.
CORRECT PROCEDURES FOR POLARIZNG THE GENERATOR VIA VR: