Diagnosing high voltage

AH OK then I'd say VR drop is good. Next, make sure the green brush connection is not grounded. Remove both field wires, check one or other brush/ field to ground for resistance, they should be OPEN / infinity. If they are, make sure VR is grounded, and if so, replace VR
What 67dart273 was asking...

With BOTH field wires disconnected.
What is the resistance red dot to green dot?


Red dot to fuschia dot