It's not necessary to remove any wires to ground the field- - - -just run a short jumper from the generator field post to ground. If the voltage at the armature post goes up, try the same field-grounding procedure at the regulator and check the voltage at the regulator ARM terminal.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!