Rotor Assembly Test

Check field slip rings for excessive wear or roughness. If slip rings have only minor damage, clean with fine emery cloth. If slip rings are badly damaged, rotor must be replaced.
Using an ohmmeter, test for continuity from one slip ring to other. See Fig 1. Continuity should exist. Test for continuity from both field coil slip rings to rotor shaft or core. Test should show open circuit. If failure is detected in either test, replace rotor assembly.

Fig 1: Testing Nippondenso Rotor Field Circuit (Chrysler Is Similar)

Courtesy of CHRYSLER MOTORS.

Fig 2: Testing Nippondenso Rotor Field Circuit For Ground (Chrysler Is Similar)

Courtesy of CHRYSLER MOTORS.