Got it, with all wires removed, there is continuity between the field terminals, at about 15 ohms or resistance, and neither terminal has continuity with ground. This is good right?
Correct. On an isolated field terminal neither brush should be in contact with ground.
As far as the 15 ohms through the rotor, its a bit high but measuring through the brushes isn't something I'd put much weight in.
Next measure green wire to ground and blue wire to ground. They should both be open (no continuity).
