Component Testing: Rotor

Check the continuity between the slip rings of the field coil. If the resistance value is not within 2-5ohm, replace the rotor. See Fig 1 .
Check the continuity between the slip ring and the core. If there is continuity, replace the rotor. See Fig 2 .

Fig 1: Checking Continuity Between Slip Rings & Field Coil

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Fig 2: Checking Continuity Between Slip Ring & Core

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.