Generator Inspection

Using a vernier caliper, measure the brush length.

Standard length:

9.5 to 11.5 mm (0.374 to 0.453 in.)

Minimum length:

4.5 mm (0.177 in.)

Check the resistance.

1. Measure the resistance between the slip rings.
   

   Standard resistance:

   1.5 to 1.9 Ω at 20°C (68°F)
   

   If the result is not as specified, replace the generator rotor assembly.
   




2. Measure the resistance between one of the slip rings and the rotor core.
   

   Standard resistance:

   1 MΩ or higher
   

   If the result is not as specified, replace the generator rotor assembly.
   

Check the slip ring diameter.

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

   Standard diameter:

   14.2 to 14.4 mm (0.559 to 0.567 in.)
   

   Minimum diameter:

   14 mm (0.551 in.)
   

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

Check the appearance.

1. Check that the bearing is not rough or worn.
   

   OK:

   The bearing rotates smoothly.
   

   If the result is not as specified, replace the generator rotor assembly.
   

Check that the bearing is not rough or worn.

OK:

The bearing rotates smoothly.

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.