Charging Systems: Generator: Inspection

INSPECT GENERATOR BRUSH HOLDER ASSEMBLY
1. Using vernier calipers, measure the exposed brush length.
  Standard exposed length: 9.5 to 11.5 mm (0.374 to 0.453 in.)
  
  Minimum exposed length: 1.5 mm (0.059 in.)
  
  If the exposed length is less than the minimum, replace the generator brush holder assembly.
  
  Fig 1: Measuring Exposed Brush Length
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT GENERATOR REGULATOR ASSEMBLY
1. Using an ohmmeter, check the continuity between terminals F and B.
  Standard:
  
  When the positive and negative poles between terminals F and B are exchanged, there is continuity in one direction but no continuity in the other direction.
  
  If the continuity is not as specified, replace the generator regulator assembly.
  
  Fig 2: Checking Continuity Between Terminals F & B
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Using an ohmmeter, check the continuity between terminals F and E.
  Standard:
  
  When the positive and negative poles between terminals F and E are exchanged, there is continuity in one direction but no continuity in the other direction.
  
  If the continuity is not as specified, replace the generator regulator assembly.
  
  Fig 3: Checking Continuity Between Terminals F & E
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT GENERATOR DRIVE END FRAME
1. Check the stator coil for open circuits.
  1. Using an ohmmeter, check the resistance between the coil leads.
    Standard resistance: Below 1 Ω
    
    If the result is not as specified, replace the generator assembly.
    
    Fig 4: Checking Resistance Between Coil Leads
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Inspect the stator for ground.
  1. Using an ohmmeter, check the resistance between the coil lead and drive end frame.
    Standard resistance: 10 kΩ or higher
    
    If the result is not as specified, replace the generator assembly.
    
    Fig 5: Checking Resistance Between Coil Lead & Drive End Frame
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Inspect the bearing.
  1. Make sure that the bearing is not rough or worn.
    If necessary, replace the generator assembly.
INSPECT GENERATOR HOLDER WITH RECTIFIER
1. Using an ohmmeter, check the continuity among terminals P1, P2, P3 and B, and among P1, P2, P3 and E.
  Standard:
  
  When the positive and negative poles among terminals P1, P2, P3 and B are exchanged, there is continuity in one direction but no continuity in the other direction.
  
  When the positive and negative poles among terminals P1, P2, P3 and E are exchanged, there is continuity in one direction but no continuity in the other direction.
  
  Fig 6: Checking Generator Holder With Rectifier
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  If the continuity is not as specified, replace the generator holder with rectifier.
INSPECT GENERATOR ROTOR ASSEMBLY
1. Check the generator rotor for open circuits.
  1. Using an ohmmeter, measure the resistance between the slip rings.
    Standard resistance: 1.7 to 2.1 Ω at 20°C (68°F)
    
    If the resistance is not as specified, replace the generator rotor assembly.
    
    Fig 7: Measuring Resistance Between Slip Rings
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Check the generator rotor for short circuits.
  1. Using an ohmmeter, check the resistance between the slip ring and generator rotor assembly.
    Standard resistance: 10 kΩ or higher
    
    If the result is not as specified, replace the generator rotor assembly.
3. Inspect the slip rings.
  1. Make sure that the slip rings are not rough or scored.
    If rough or scored, replace the generator rotor assembly.
    
    Fig 8: Checking Resistance Between Slip Ring & Generator Rotor Assembly
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. Using vernier calipers, measure the slip ring diameter.
    Standard diameter: 14.2 to 14.4 mm (0.559 to 0.567 in.)
    
    Minimum diameter: 12.8 mm (0.504 in.)
    
    If the diameter is less than the minimum, replace the generator rotor assembly.
    
    Fig 9: Measuring Slip Ring Diameter
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002