Is there any component attached to the leads or still in circuit when you try and spin it with the brushes down?
Max.

 

Then it would point to the motor, can you remove the brushes and make sure they are not in contact with the comm?
Another test, is if you place a voltmeter on the leads and rotate the armature as fast as possible, it should generate.
Max.

Sorry I missed this reply. By reassembling the grinder and rotating the output shaft I was able to get .5 volts. Didn't get too fancy with a winder so it wasn't very fast. Does this give some clues to the grinders problem?

 

I would expect a lot more than that, even at low voltage, indicates more is wrong with the motor.
Max.

 

Thanks, maybe it's a dead grinder.

 

Suggests a bad motor.
Max.

 

Is there any component attached to the leads or still in circuit when you try and spin it with the brushes down?
Max.

Spinning it with the brushes down the 'electronic module is still on the black lead.

 

how do the windings look like? if they are discolored (dark) on the surface, motor was cooked and it is much worse below surface. in that case insulation is probably damaged and you are getting shorts.

 

how do the windings look like? if they are discolored (dark) on the surface, motor was cooked and it is much worse below surface. in that case insulation is probably damaged and you are getting shorts.

Thats the odd part, except for a little discolouration on the terminals on the 'electronic module' everything looks pristine!