DIAGNOSIS WARNING
When any of the following problems occur, the charge light will illuminate.
- No voltage generation: Brush wear exceeds specified limits, field coil circuit is broken, etc.
- Excessive output: Output voltage is greater than about 16 volts.
- Terminal "B" disconnection: Harness is disconnected from generator terminal "B".
- Terminal "S" disconnection: Harness is disconnected from generator terminal "S". In this case, voltage is slightly greater than specified regulated voltage; however, voltage regulation is still controlled and battery is prevented from being overcharged.
TROUBLE SHOOTING
Note. See TROUBLE SHOOTING - BASIC PROCEDURES article in the GENERAL TROUBLE SHOOTING section.
ON-VEHICLE TESTING
- Turn ignition switch to RUN position. Check charge indicator light. If indicator light illuminates, go to next step. If indicator light does not illuminate, turn engine off and go to step 5).
- Start engine and let idle. Check charge indicator light. If indicator light does not illuminate or blink, go to next step. If indicator light is still illuminated or blinks, check fan belt tension, check "S" and "B" terminals for proper contact and check generator output. See «GENERATOR OUTPUT SPECIFICATIONS»(ref-124873-S09451540592001100200000) table.
- Check voltage at battery terminals. If voltage is 12.5-15.5 volts, go to next step. If voltage is greater than 15.5 volts, replace regulator assembly. If voltage is less than 12.5 volts, check IC voltage regulator. If regulator is okay, replace generator assembly as necessary.
- Turn headlights on. Check charge indicator bulb. If indicator light illuminates or blinks, check diode assembly. See «DIODE ASSEMBLY»(ref-124873-S26006934102001100200000) under BENCH TESTING. If indicator light does not illuminate or blink, system is functioning properly at this time.
- Disconnect generator harness connector. Ground terminal "L" (Brown wire) at generator harness connector. Turn ignition switch to RUN position, engine off. Check charge indicator light. If indicator light does not illuminate, repair indicator light circuit and/or replace bulb. If indicator light illuminates, check IC voltage regulator and positive terminal of diode. See «DIODE ASSEMBLY»(ref-124873-S26006934102001100200000) under BENCH TESTING.
| Engine RPM | Amps | |
|---|---|---|
| Forester | (2) | |
| Impreza | ||
| 1500 | 30 Or Greater | |
| 2500 | 64 Or Greater | |
| 5000 | 76 Or Greater | |
| (1) Regulated voltage is 14.2-14.8 volts at 68°F (20°C). (2) Information is not available. | ||
| (1) | Regulated voltage is 14.2-14.8 volts at 68°F (20°C). |
| (2) | Information is not available. |
GENERATOR OUTPUT SPECIFICATIONS (1)
Testing Positive Diode
Check continuity between diode lead and positive side of heat sink. Connect ohmmeter positive lead to diode lead and negative lead to heat sink. Continuity should exist. Reverse ohmmeter leads. Continuity should not exist.
Testing Negative Diode
Check continuity between diode lead and negative side of heat sink. Connect ohmmeter negative lead to diode lead and positive lead to heat sink. Continuity should exist. Reverse ohmmeter leads. Continuity should not exist.
Testing Diode Trio
To check diode assembly (diode trio), remove assembly from rear cover. Using an ohmmeter, check each diode for continuity. Continuity should be present in one direction only. If continuity is present in both directions, or continuity does not exist in either direction, diode is faulty. If any diodes are faulty, replace complete rectifier assembly.