Alternator: Testing and Inspection

2TR-FE CHARGING: GENERATOR: INSPECTION

INSPECTION





1. INSPECT GENERATOR BRUSH HOLDER ASSEMBLY
(a) Using vernier calipers, measure the exposed brush length.
Standard exposed length:
9.5 to 11.5 mm (0.374 to 0.453 in.)
Minimum exposed length:
4.5 mm (0.177 in.)
If the exposed length is less than the minimum, replace the generator brush holder assembly.
2. INSPECT GENERATOR REGULATOR ASSEMBLY





(a) Using an ohmmeter, check the continuity between terminals F and B.
Standard:
When the positive and negative poles between terminals F and B are exchanged, there is continuity in one way but no continuity in another way.
If the continuity is not specified, replace the generator regulator assembly.





(b) Using an ohmmeter, check the continuity between terminals F and E.
Standard:
When the positive and negative poles between terminals F and E are exchanged, there is continuity in one way but no continuity in another way.
If the continuity is not specified, replace the generator regulator assembly.





3. INSPECT GENERATOR HOLDER WITH RECTIFIER
(a) Using an ohmmeter, check the continuity between terminals P1, P2, P3, P4 and B, and between P1, P2, P3, P4 and E.
Standard:





If the continuity is not as specified, replace the generator rectifier holder.
4. INSPECT GENERATOR ROTOR ASSEMBLY





(a) Check for open in the generator rotor circuit.
(1) Using an ohmmeter, measure the resistance between the slip rings.
Standard resistance:
1.7 to 2.1 Ohms at 20°C (68°F)
If the resistance is not as specified, replace the generator rotor assembly.





(b) Check for short in the generator rotor circuit.
(1) Using an ohmmeter, check that there is no continuity between the slip ring and generator rotor assembly.
If there is continuity, replace the generator rotor assembly.
(c) Inspect the slip rings.
(1) Check that the slip rings are not rough or scored.
If rough or scored, replace the generator 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 generator rotor assembly.
5. INSPECT GENERATOR PULLEY WITH CLUTCH





(a) Hold the center of the pulley, and confirm that the outer ring turns counterclockwise and does not turn clockwise.
If the result is not as specified, replace the generator pulley with clutch.