Charging Systems: Generator: Inspection

1. Check the rotor for open circuit.

   Using an ohmmeter, check that there is continuity between the slip rings.

   Standard Resistance  : 2.3-2.7 ohms at 20°C (68°F)

   If there is no continuity, replace the rotor.

   Fig 1: Checking Rotor For Open Circuit

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Check the rotor for ground.

   Using an ohmmeter, check that there is no continuity between the slip ring and rotor.

   If there is continuity, replace the rotor.

   Fig 2: Checking Rotor For Ground

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Check that the slip rings are not rough or scored.

   If rough or scored, replace the rotor.

4. Using vernier calipers, measure the slip ring diameter.
   1. Standard Diameter  : 14.2-14.4 mm (0.559-0.567 in.)
   2. Minimum Diameter  : 14.0 mm (0.551 in.)

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

   Fig 3: Checking Slip Rings

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Using a vernier caliper, measure the exposed brush length.

1. Standard Exposed Length  : 10.5 mm (0.413 in.)
2. Minimum Exposed Length  : 4.5 mm (0.177 in.)

If the exposed length is less than minimum, replace the brushes and brush holder assembly.

Check the bearing is not rough or worn.

If necessary, replace the bearing. See REPLACEMENT .

Fig 4: Displaying Brushes Inspection

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002