Generator Inspection

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	20°C (68°F)	2.1 to 2.5 Ω

   Text in Illustration

   *1

   Slip Ring

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

Check if the generator rotor is grounded.

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

   Standard Condition:

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

   Text in Illustration

   *1	Slip Ring
   *2	Rotor Core

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

Check that the slip rings are not rough or scored.
If they are rough or scored, replace the generator rotor assembly.

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:

14.0 mm (0.551 in.)

Inspect the bearing.

1. Check that the bearing is not rough or worn.
   If necessary, replace the generator rotor assembly.
   

Check the stator for an open circuit.

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

   Standard Resistance:

   Tester Connection	Condition	Specified Condition
   Coil lead - Coil lead	Always	Below 1 Ω

   Text in Illustration

   *1

   Coil Lead

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

Check the stator for a short circuit.

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

   Standard Resistance:

   Tester Connection	Condition	Specified Condition
   Coil lead - Drive end frame	Always	10 kΩ or higher

   Text in Illustration

   *1	Coil Lead
   *2	Drive End Frame

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

Inspect the bearing.

1. Check that the bearing is not rough or worn.
   If necessary, replace the generator assembly.
   

Using a vernier caliper, 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.)

Check the positive terminal of the rectifier.

1. Using an ohmmeter, connect one tester probe to the positive (+) terminal and the other to each rectifier terminal.
   

2. Reverse the polarity of the tester probes and repeat the step above.
   

3. Check that one polarity 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 holder with rectifier.
   

Check the negative terminal of the rectifier.

1. Using an ohmmeter, connect one tester probe to the negative (-) terminal and the other to each rectifier terminal.
   

2. Reverse the polarity of the tester probes and repeat the step above.
   

3. Check that one polarity 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 holder with rectifier.
   

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
Terminal F - Terminal B	Always	Below 1 Ω or higher than 10 kΩ

HINT:

When the ohmmeter leads are initially touched to the regulator, one of the above values is output. When the leads are reversed, the reading changes to the other value.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
Terminal F - Terminal E	Always	Below 1 Ω or higher than 10 kΩ

HINT:

When the ohmmeter leads are initially touched to the regulator, one of the above values is output. When the leads are reversed, the reading changes to the other value.