INSPECT GENERATOR ROTOR ASSEMBLY
Check the rotor for an open circuit.
Measure the resistance between the slip rings.
| Standard resistance |
|---|
| 1.8 to 2.8 Ωat 20°C (68°F) |
If the result is not as specified, replace the rotor assembly.
Check if the rotor is grounded.
Measure the resistance between the slip ring and rotor.
| Standard resistance |
|---|
| 10 kΩ or higher |
If the result is not as specified, replace the rotor assembly.
Check that the slip rings are not rough or scored.
If rough or scored, replace the rotor assembly.
Using a vernier caliper, measure the slip ring diameter.
| Standard diameter |
|---|
| 15.3 to 15.5 mm (0.602 to 0.610 in.) |
| Minimum diameter |
|---|
| 14.9 mm (0.587 in.) |
If the diameter is less than the minimum, replace the rotor assembly.
INSPECT GENERATOR STATOR SUB-ASSEMBLY WITH RECTIFIER
Tech Tips
For terminal positions of the stator generator, refer to the illustration below.
Inspect the positive (+) rectifier.
Tech Tips
Inspect the positive terminal after pulling it up.
Using an ohmmeter, connect one tester probe to the positive (+) terminal and the other to each rectifier terminal.
Reverse the polarity of the tester probes and repeat the step above.
Check that one shows a resistance of below 1 Ω and the other shows a resistance of 10 kΩ or higher.
If the result is not as specified, replace the generator stator sub-assembly with rectifier.
Inspect the negative (-) rectifier.
Using an ohmmeter, connect one tester probe to each negative (-) terminal and the other to each rectifier terminal.
Reverse the polarity of the tester probes and repeat the step above.
Check that one shows a resistance of below 1 Ω and the other shows a resistance of 10 kΩ or higher.
If the result is not as specified, replace the generator stator sub-assembly with rectifier.
Inspect the stator coil for an open circuit.
Measure the resistance between the rectifier terminals.
| Standard resistance |
|---|
| Below 1 Ω |
If the result is not as specified, replace the generator stator sub-assembly with rectifier.
INSPECT BRUSH
Using a vernier caliper, measure the exposed brush length.
| Standard exposed length on new brush |
|---|
| 13.2 mm (0.520 in.) |
| Minimum exposed length |
|---|
| 6.0 mm (0.236 in.) |
If the exposed length is less than the minimum, replace the generator regulator sub-assembly with brush.