Component Tests and General Diagnostics

GENERATOR INSPECTION

CAUTION: Do not apply direct battery positive voltage to the generator terminal D, otherwise it could cause damage to the internal parts (power transistor) of the generator.

Generator warning light

1. Verify that the battery is fully charged.
2. Verify that the drive belt deflection/tension is within the specification.
3. With the ignition switch at ON, verify that the generator warning light illuminates.
- If it does not illuminate, inspect the generator warning light and the wiring harness.
- If the generator warning light and the wiring harness are normal, inspect the PCM.
4. Verify that the generator warning light turns off after the engine is started.
- If it does not turn off, check if any one of the following DTCs in the on-board diagnostic system are displayed: P0112, P0113, P2502, P2503, P2504.

Generator

Voltage
1. Verify that the battery is fully charged.
2. Verify that the drive belt deflection/tension is within the specification.
3. Turn off all electrical loads.
4. Start the engine and verify that the generator rotates smoothly without any noise while the engine is running.







5. Measure the voltage at each terminal using a tester.

Current
1. Verify that the battery is fully charged.
2. Verify that the drive belt deflection/tension is within the specification.
3. Disconnect the negative battery cable
4. Connect a tester capable of reading 120 A or above between generator terminal B and the wiring harness.
5. Connect the negative battery cable.
6. Turn off all electrical loads.
7. Start the engine.
8. Increase engine speed from 2,000 - 2,500 rpm.
9. Turn the following electrical loads on and verify that the current reading increases.
- Headlights
- Blower motor
- Rear window defroster

NOTE: Current required for generating power varies with electrical loads applied.




Reference value
Current possible for power generation (differs according to load)
[Conditions] ambient temperature 20° C {68 °F}, voltage 13.0 - 15.0 V, engine warm

Generator Inner Parts
Rotor




1. Measure the resistance between the slip rings using an ohmmeter.
- If not as specified, replace the rotor.

Resistance [20 °C {68 °F}]
1.6-2.0 Ohms




2. Verify that there is no continuity between the slip ring and core using an ohmmeter.
- If there is continuity, replace the rotor.
3. Inspect the slip ring surface condition.
- If the slip ring surface is rough, use a lathe or fine sandpaper to repair it.

Stator coil




1. Inspect for continuity between the stator coil leads using an ohmmeter.
- If there is no continuity, replace the stator.




2. Verify that there is no continuity between the stator coil leads and the core using an ohmmeter.
- If there is continuity, replace the stator coil.

Brush




1. Inspect brushes for wear.
- If any brush is worn almost to or beyond the limit, replace all of the brushes.

Standard brush length 18.5 mm {0.73 in}
Minimum brush length 5.0 mm {0.2 in}

Brush spring




1. Measure the force of the brush spring using a spring pressure gauge.
2. Read the spring pressure gauge at the brush tip projection of 2 mm {0.079 in}.
- Replace the brush spring if necessary.

Standard spring force
4.8 - 6.0 N {0.49 - 0.61 kgf, 1.08 - 1.34 lbf}
Minimum spring force
2.16 N {0.22 kgf, 0.49 lbf}

Rectifier










1. Inspect for continuity of the diodes using an ohmmeter.
- If not as specified, replace the rectifier.

Bearing




1. Inspect for abnormal noise, looseness, and sticking.
- Replace the bearing if necessary.