wiring question

My 1941 farmall BN i got last weekend at an auction almost started after cleaning the points and new gas after sitting for who knows how long.
One plug wire was bad also.
I have a new carb kit and points, rotor etc coming soon.
There is a wire that looks like it came off something near the generator. Its a small solid wire (#16 size maybe).
The only place it looks like it may go is on the F terminal on the voltage regulator.
I tried looking it up but cant find anything.
What is the F terminal even for?

F is for field. Sounds like a previous owner might have had a charging
problem.

Would you believe the ignition circuit and generator circuit are two different circuits and yo can run it with out the generator.

I would clean the points real good and then try a hot wire. Then I would check the spark at all the plugs and make sure you have a nice blue/white spark

Not sure which charging system that has.

If it has a cut out relay, the F terminal goes to the resistor on the headlight switch.

If it has a regulator, the F terminal goes to the F terminal on the regulator.

Follow the wire, see where it goes, that should give you some clue.

Good questions, lets work through them one t a time.

1) "There is a wire that looks like it came off something near the generator. Its a small solid wire (#16 size maybe).
The only place it looks like it may go is on the F terminal on the voltage regulator."

From what you say (if correct) iffffffff it actually has a "Voltage Regulator" ??? (not a Cutout Relay) and iffffffffffffffff it has a F terminal as you say ??? and iffffffffffff that wire is connected to the generators F post ???

THEN IT SHOULD CONNECT FROM F POST ON THE GENNY TO THE F TERMINAL ON THE VOLTAGE REGULATOR

2) "What is the F terminal even for?"

The F "Post" on the Generator connects to its Field winding. The F "Terminal" on the Voltage Regulator supplies a regulated ground to control charging.

SUMMARY F Post on Genny wires to F terminal on Voltage Regulator

If instead of a Voltage Regulator as you claim it had a Cutout Relay, the Gennys F Post wires up to the LHDB headlight switch and NOT the Voltage Regulator

Ignition doesn't rely on the Generator (still has to have a charge battery to work) and Generator doesn't rely on Ignition, those are different systems.

To see if the Generator is charging when its running, ground out the gennys F post and see if ammeter shows charge or battery voltage rises?? If so but NOT otherwise, the VR is bad or not well grounded or on a cutout relay system the gennys F post isnt getting a good ground cuz the light switch isn't well grounded or a wires missing from F on genny to light switch.

John T

Our 1941 BN doesn't have starter nor an electrical system. We used it a lot for a mower tractor though. It had several different mowers that we modified to attach to the drawbar. The last sickle mower that it pulled was a New Idea trailer type with the heaviest,thickest cutter bar that I've ever seen on a mower. It wouldn't bounce over a gopher mound; it just shaved off the top of the mound!

Try this
Bob Nelvilles wiring diagram