Alternator: Testing and Inspection

1GR-FE CHARGING: GENERATOR: INSPECTION

INSPECTION





1. INSPECT GENERATOR BRUSH HOLDER ASSEMBLY
(a) Using vernier calipers, measure the exposed brush length.
Standard exposed brush length:
10.5 mm (0.413 in.)
Minimum exposed brush length:
4.5 mm (0.177 in.)
If the exposed brush length is less than the minimum, replace the brush holder.
2. INSPECT GENERATOR ROTOR ASSEMBLY





(a) Check the rotor for an open circuit.
(1) Using an ohmmeter, measure the resistance between the slip rings.
Standard resistance:
2.3 to 2.7 Ohms at 20°C (68°F)
If the resistance is not as specified, replace the rotor.





(b) Check the rotor for ground.
(1) Using an ohmmeter, check the resistance between the slip ring and rotor.
Standard resistance:
10 kOhms or higher
If there is continuity, replace the rotor.
(c) Inspect the slip rings.
(1) Check that the slip rings are not rough or scored.
If rough or scored, replace the rotor assembly.




(2) Using vernier calipers, measure the slip ring diameter.
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 less than the minimum, replace the rotor.





3. INSPECT GENERATOR ROTOR BEARING
(a) Check that the bearing is not rough or worn.
If necessary, replace the generator rotor assembly.





4. INSPECT GENERATOR DRIVE END FRAME BEARING
(a) Check that the bearing is not rough or worn.
If necessary, replace the bearing.