System GEN will run on 6V/POS GRN or 12V NEG GRN but, it must be wired for correct polarization. Normally the GEN will be set upon rebuild for either or by the shop
rebuilder. Polarizing can be done using your VR too but you must know which circuit you are using. There is an A Circuit and a B Circuit. It's very important to
know which is which. Polarizing the wrong way will result in a fried VR. Unless you have the first early 9N small GEN using a VR and the B Circuit, all GENS after
1940 used an A Circuit GEN. With the NAA came the B Circuit Design using a new VR as well, and all after remained as such. Yes, FORD wired the new diesel models
as 12V/NEG GRN and used a VR as well. If'N it were me, and I had a 12V battery, I'd opt to go all the way and install a Delco-Remy 10SI ALTERNATOR and eschew the
original GEN and VR. With this setup, and keeping the OEM 6V coil, you need to add an inline externa 1-OHM Resistor in the coil circuit to meet specs. By swapping out
to a 12V verified coil, you eliminate the need for an added external resistor. 12V has advantages - faster starting, good for a worn engine, brighter lights, and can
run 12V equipment like your old Pioneer Super-Tuner 8-Track Player. When going to 12V any 6V lamps must be changed out to 12V Lamps or elSe at power up you will blow
the 6V lamps. FYI: 6V Sealed Beam Lamps = Industry Standard 4019; 12V Industry Standard Sealed Beam Lamps = 4419. PICTOGRAMS shown using the DELCO 10SI ALTERNATOR, a
1-WIRE, RELIABLE AND PROVEN EFFECTIVE device ford FORD Tractor conversions.
NAA 12V Wiring:
NOTE: Shown if using a 12V Coil.
NAA 12V WIRING if using the 6V COIL; NEED THE INLINE EXTERNAL 1-OHM RESISTOR ADDITION.
Tim Daley (MI)