Flywheel Coils test for Model F

How do the if the commutator coils are good ? Not sure if I'm using the correct term. It the one that bolts to flywheel !

For more information, look up Ford Model T magneto coils, as the Fordson tractor used the same kind of system (flywheel, magnets, coils)(and at the time it was called a "magneto" by Ford)(the flywheel with magnets revolves while the magneto coils remain stationary). I think that you should be able to use an Ohm meter ( one lead on the magneto post and the other on the engine block). I believe that the magneto coils are wired in series with one end being connected to the magneto post and the other end being connected to ground (engine block). One source mentioned a value of 1/4 to 1/2 Ohm for a resistance value. If there is no continuity or if the resistance value is very high, you would probably have to split the tractor to fix the coils or connections. There is a Fordson model "F" out at the farm, and I will try to measure the resistance in the next few days. Have never tried to use the magneto, as I always just used a 6 Volt battery (to power the ignition coils (buzz boxes). The reproduction Fordson and Model "T" manuals do not mention testing the magneto (and Ohm meters were not common a long time ago). And finally, please note that when Ford used the term "magneto" for the Fordson model "F", it is totally different than the common tractor magneto (which produces the high voltage for the spark plugs). The Fordson magneto is really an AC generator (alternator) that is used to power the ignition buzz coils.

Just got back from the farm. Measured about 1/2 Ohm (magneto post to engine block). Kinda hard to measure low values of resistance when the meter leads measure about 0.2 Ohms when touched together.
So the real test for the magneto is to get a #1156 bulb and socket (like a tail light bulb), connect it (one lead on the magneto post and one on the engine block)and then spin the crank. Look for the bulb to illuminate. This would test both the coils and the magnets. Don't know if a LED bulb would work the same. Hope to be able to test this tomorrow.

I have the coils out ,i will test it .before I install , thanks