Armature Coil Check

CAUTION: Clean the surface of the armature thoroughly before performing the test.

Place armature in a growler. See Fig 1 .
While holding a thin strip of iron against the armature in parallel with its axis, turn the armature slowly. The armature is normal if the iron strip is not attract to the armature or it does not vibrate.
Check the insulation between commutator segments and armature coils. See Fig 2 . The armature coils are properly insulated if no continuity is present.
Check continuity between a segment and another. There is no open circuit in the tested coil if there is continuity. See Fig 3 .

Fig 1: Placing Armature In Growler

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Fig 2: Checking Armature Coil Ground Test

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Fig 3: Checking Armature Coil Open Circuit

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.