Testing Motor Armature - Mercury 15XD Service Manual

BATTERY CHARGING AND STARTING SYSTEMS

Testing Motor Armature

TESTING ARMATURE FOR SHORTS
1. Place armature in a growler and switch growler on.
2. Hold hack saw blade over armature core while rotating armature.
3. If saw blade vibrates, armature is shorted. Retest after cleaning between commutator
bars. If saw blade still vibrates, replace armature.
a -
b -
c -
TESTING ARMATURE FOR GROUND
1. Use an ohmmeter (R x 100) to check for " no continuity"between commutator and ar-
mature core or commutator and shaft.
2. If continuity exists, armature is grounded and must be replaced.
a -
b -
c -
Page 2B-18
a
c
Hack Saw Blade
Armature Core
Commutator
c
Commutator
Armature Core
Shaft
b
01440
b
a
01441
90-826883R2 JUNE 1998