No, that's actually normal. The Armature terminal will have virtually zero resistance when checked with an ammeter. The field terminal will have several ohms of resistance, since you're reading the resistance of the field coils, and eventually through the armature windings to ground. The only effective way to check a generator without a shop full of equipment is the "polarize- - - -residual voltage- - - -grounded field" check I described. Anything else requires specialized test equipment most hobbyists don't have unless they're named "Denny".
LOL!
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!