Mercury Electric Outboards 222 Thruster Service Manual, Page 47Get this manual
Testing Motor Armature CHECKING ARMATURE for SHORTS
Check armature for short circuits, as follows: 1Place armature in growler and switch growler on2Hold hack saw blade over armature core while rotating armature(Figure 3) 3If saw blade vibrates, armature is shorted Replace armature
CHECKING ARMATURE for GROUND
1Use VOA meter (RxlOO scale) to check for "no continuity" between commutator and armature core or commutator and shaft(Figure 4) Ifcontinuity" exists between commutator and armature core or shaftarmature is grounded and must be replaced