Alternator: Testing and Inspection

1UR-FSE CHARGING: GENERATOR: INSPECTION

1. INSPECT GENERATOR BRUSH HOLDER ASSEMBLY





(a) Using a vernier caliper, measure the exposed brush length.

Standard length:

10.5 mm (0.413 in.)

Minimum length:

4.5 mm (0.177 in.)

If the exposed brush length is less than the minimum, replace the generator brush holder assembly.

2. INSPECT GENERATOR ROTOR ASSEMBLY





(a) Inspect the bearing.

(1) When rotating the bearing, check that the bearing does not become stuck and that there is no unusual noise.

If the bearing becomes stuck or there is unusual noise, replace the generator rotor assembly.

(b) Measure the resistance.





(1) Measure the resistance between the slip rings.

Standard resistance:

1.5 to 1.9 Ohms

If the resistance is not within the specified range, replace the generator rotor assembly.

(2) Measure the resistance between the slip ring and rotor core.





Standard resistance:

1 MOhms or more

If the resistance is not within the specified range, replace the generator rotor assembly.

(c) Measure the diameter.





(1) Using a vernier caliper, measure the diameter of the slip ring.

Standard diameter:

14.2 to 14.4 mm (0.559 to 0.567 in.)

Minimum diameter:

14.0 mm (0.551 in.)

If the diameter is not within the specified range, adjust the diameter with sandpaper (#400).

If the diameter is less than the minimum, replace the generator rotor assembly.

3. INSPECT GENERATOR ROTOR BEARING





(a) When rotating the bearing, check that the bearing does not become stuck and that there is no unusual noise.

If the bearing becomes stuck or there is unusual noise, replace the generator rotor bearing.