Generator Inspection

Rotor
Open circuit




Using ohmmeter, check for continuity between slip rings of rotor. If there is no continuity, replace rotor.




Ground
Using ohmmeter, check that there is no continuity between slip ring and rotor. If there is continuity, replace rotor.

Slip rings




- Check slip rings for roughness or scoring. If rough or scored, replace rotor.
- Using a vernier caliper, measure the slip ring diameter. If the diameter is less than minimum, replace the rotor.

Stator
Open circuit




Using ohmmeter, check all leads for continuity. If there is no continuity, replace stator.

Ground




Using ohmmeter, check that there is no continuity between coil leads and stator core. If there is continuity, replace stator.

Brush and Brush Holder




Check each brush for wear by measuring its length.

[Type a]
If brush is found worn down to service limit, replace brush.

[Type b]
If brush is found worn down to service limit, replace brush and brush holder.

Positive rectifier




1. Using an ohmmeter, connect one tester probe to the "B" terminal (1) and the other to each rectifier terminal (2).
2. Reverse the polarity of the tester probes and repeat Step 1.
3. Check that one shows continuity and the other shows no continuity. If there is continuity, replace the rectifier.

Negative rectifier




1. Using an ohmmeter, connect one tester probe to each negative terminal (1) and the other to each rectifier terminal(2).
2. Reverse the polarity of the tester probes and repeat Step 1.
3. Check that one shows continuity and the other shows no continuity.

Bearing

Drive end bearing




Check that the bearing is not rough or worn.

End housing bearing




Check that the bearing is not rough or worn.
When removal is necessary, refer to "Generator Disassembly and Assembly:".