Armature Test
- Test armature for shorted coils with a growler. Check for grounded coils with a test light. Place one lead on armature shaft and other lead on commutator. Test light should not light. If test light lights, armature is grounded. Replace armature.
- Turn commutator if it is rough, worn, or has protruding insulation. DO NOT turn to less than 1.65" (41.9 mm) diameter. Sand commutator lightly.