Originally Posted by newyear
...The end plate has the Fomoco logo impressed on it and the body is marked with G and F and 12V...
Yes, 'G' is the ground terminal, 'F' is the field terminal. There should be one more marked, 'A' for armature:
I've seen starter motors and generators, freshly rebuilt but they refused to work because too much paint was applied to the end plate. This insulated it from ground. It doesn't take much to hold back six or twelve volts.
As with the starter motors, generators came in 6-volt and 12-volt versions. They both look identical from the outside, brushes may be the same as well but field windings are quite different.
It may be that Ford produced their own generators and starter motors but I have to believe that vendors also helped, given the numbers required to keep up with 20 assembly plants and service parts. These parts were used in cars (Ford, Lincoln, Edsel, Mercury), trucks, construction equipment, marine and tractors. The same starter motors and generators were assembled in Flat Head, Y-Block, FE, and MEL engines with only slight variations. For instance, they moved the starter post in MEL engines because it was in the way of the exhaust manifold. - Dave