Generator Inspection

Hold the center of the generator pulley, and confirm that the outer ring turns counterclockwise and does not turn clockwise.

Using a vernier caliper, measure the length of the exposed brushes.

Standard exposed length:

9.5 to 11.5 mm (0.374 to 0.453 in.)

Minimum exposed length:

4.5 mm (0.177 in.)

Check the generator rotor for an open circuit.

1. Measure the resistance according to the value(s) in the table below.
   

   Standard Resistance:

   Tester Connection	Condition	Specified Condition
   Slip ring - Slip ring	Approx. 20°C (68°F)	2.3 to 2.7 Ω

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

Check the generator rotor for a short to ground.

1. Measure the resistance according to the value(s) in the table below.
   

   Standard Resistance:

   Tester Connection	Condition	Specified Condition
   Slip ring - Rotor	Always	10 kΩ or higher

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

Check that the generator rotor bearing is not rough or worn, and that it rotates smoothly.
If the result is not as specified, replace the generator rotor assembly.

Using a vernier caliper, measure the diameter of each slip ring.

Standard diameter:

14.2 to 14.4 mm (0.559 to 0.567 in.)

Minimum diameter:

14.0 mm (0.551 in.)

Check that the generator rotor bearing is not rough or worn, and that it rotates smoothly.
If the result is not as specified, replace the generator rotor bearing.