Charging Systems: Generator: Inspection

INSPECT VOLTAGE REGULATOR
1. Using an ohmmeter, check the continuity between terminals F and B.
  
  Fig 1: Checking Continuity Between Terminals F And B
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Standard:
  
  When the positive and negative poles between terminals F and B are exchanged, there is continuity in one way but no continuity in another way.
  
  If the continuity is not as specified, replace the voltage regulator.
2. Using an ohmmeter, check the continuity between terminals F and E.
  
  Fig 2: Checking Continuity Between Terminals F And E
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Standard:
  
  When the positive and negative poles between terminals F and E are exchanged, there is continuity in one way but no continuity in another way.
  
  If the continuity is not as specified, replace the voltage regulator.
INSPECT ROTOR FOR OPEN CIRCUIT
Using an ohmmeter, check that there is continuity between the slip rings.

Fig 3: Inspecting Rotor For Open Circuit
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Standard resistance:

2.1 - 2.5 Ω at 20° C (68° F)

If there is no continuity, replace the rotor.
INSPECT ROTOR FOR GROUND
Using an ohmmeter, check that there is no continuity between the slip ring and rotor.

Fig 4: Inspecting Rotor For Ground
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If there is continuity, replace the rotor.
INSPECT SLIP RINGS
1. Check that the slip rings are not rough or scored.
  If rough or scored, replace the rotor.
2. Using vernier calipers, measure the slip ring diameter.
  
  Fig 5: Measuring Slip Ring Diameter
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Standard diameter:
  
  14.2 - 14.4 mm (0.559 - 0.567 in.)
  
  Minimum diameter:
  
  12.8 mm (0.504 in.)
  
  If the diameter is less than minimum, replace the rotor.
INSPECT STATOR FOR OPEN CIRCUIT
Using an ohmmeter, check that there is continuity between the coil leads.

Fig 6: Inspecting Stator For Open Circuit
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If there is no continuity, replace the drive end frame assembly.
INSPECT STATOR FOR GROUND
Using an ohmmeter, check that there is no continuity between the coil lead and drive end frame.

Fig 7: Inspecting Stator For Ground
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If there is continuity, replace the drive end frame assembly.
INSPECT EXPOSED BRUSH LENGTH
Using vernier calipers, measure the exposed brush length.

Fig 8: Inspecting Exposed Brush Length
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Standard exposed length:

10.5 mm (0.413 in.)

Minimum exposed length:

1.5 mm (0.059 in.)

If the exposed length is less than minimum, replace the brush holder.
INSPECT POSITIVE 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 step (a).
3. Check that one shows continuity and the other shows no continuity.
If continuity is not as specified, replace the rectifier holder.
INSPECT NEGATIVE RECTIFIER
1. Using an ohmmeter, connect one tester probe to each negative (-) terminal and the other to each rectifier terminal.
2. Reverse the polarity of the tester probes and repeat step (a).
3. Check that one shows continuity and the other shows no continuity.
If continuity is not as specified, replace the rectifier holder.
INSPECT FRONT AND REAR BEARING
Check that the bearing is not rough or worn.

If necessary, replace the bearing.