Starting/Charging (H4SO): Generator: Inspection: Rotor

Check that there is no dirt on the slip ring or roughness in the sliding surface. Repair the slip ring surface using a lathe or sand paper.

Measure the slip ring outer diameter. Replace the rotor assembly if the slip ring is worn.

Slip ring outer diameter: 

Standard: 22.7 mm (0.894 in) 

Tolerance limit value: 22.1 mm (0.870 in) 

Using a circuit tester, check the resistance between slip rings.

Replace the rotor assembly if the resistance is not within the specified value.

Specified resistance: Approximately 1.8 - 2.2 Ω 

Fig 1: Checking Resistance Between Slip Rings

Check the continuity between the slip ring and the rotor core or shaft. If the resistance is 1Ω or less, replace the rotor assembly because the rotor coil is grounded.

Fig 2: Checking Continuity Between Slip Ring And Rotor Core Or Shaft

Check the rear ball bearings. If there is any noise, or the rotor does not rotate smoothly, replace.