Wiring diagram for B

Thanks, Wes

• Wire Diagram

Ammeter minus- to Bat. terminal on VR Gen terminal on VR to "A" (Armature) stud on gennie
Field terminal (FLD) to "F" stud on gennie.
"L" terminal on VR not used if equipped

If your utilizing the OEM "cutout" it's wired this way:
Ammeter minus (-) to BAT terminal on cutout
Gen terminal on cutout to "A" stud on gennie
"F" stud on gennie to resistor on H/L switch If the gennie is rebuilt correctly, and the 3 position headlight switch is grounded correctly, it should charge. Make sure the H/L switch is grounded! That's how the system is designed. HTH
Steve@B&B

As far as I know the B never had a true automatic voltage regulator provided by AC. I think that is the case for either a magneto or a distributor ignition. The OEM arrangement only had a generator cutout relay that automatically disconnected the generator from the battery whenever the engine was stopped. The regulation of the generator was done manually with the three position light switch in the instrument panel. There were only two generator charging rates...low and high when the engine was running, depending on the position of the light switch. The wiring diagram in the AC B/C service manual shows only the mag-equipped tractor. I would expect that the only difference is in the switching function in the wire connection to either the mag or the distributor. I think the generator charging circuit was the same in either case.

If you have a true regulator (two relays in one package) on your generator, I suspect that it was an aftermarket alteration by someone. I did that same alteration on my '42B until I decided later to simply convert to a 12V alternator. As I recall, it wasn't a difficult wiring installation. If you know that it is the original, externally grounded, third brush style generator, you might get some ideas from this article here at YT.

Rod