Rotor Inspection

Measure resistance between slip rings with a ohmmeter. If it is not within standard resistance, replace rotor. See Fig 1 . Standard resistance: 3.5-4.5ohm

Fig 1: Measuring Resistance Between Slip Rings
Courtesy of KIA MOTORS AMERICA, INC.
Check for continuity between slip ring and core with a circuit tester. Replace rotor if there is continuity. See Fig 2 .

Fig 2: Checking Continuity Between Slip Ring & Core
Courtesy of KIA MOTORS AMERICA, INC.
If slip ring surface is rough, smooth with a lathe or fine sandpaper.