System Performance Test

Fig. 2 Alternator Charging System.:

Charging systems in Fig. 2, are equipped with self-diagnostic capabilities which monitor system operation and alert driver to malfunctions. Problems sensed in system operation will be indicated by illumination of the alternator warning lamp.

Fig. 5 Normal Alternator Operation Voltage Specifications:

NORMAL SYSTEM OPERATION

When alternator system is functioning normally, system voltages will be as specified, Fig. 5.

WARNING LIGHT INSPECTION

Turn ignition switch "ON" and ensure warning light illuminates. Start engine and ensure warning light goes off. If light does not go off, refer to WARNING LIGHT STAYS ON.

WARNING LIGHT WILL NOT ILLUMINATE

1. Turn ignition "ON" and ensure other warning lamps illuminate. If not, check for bad fuse or wiring harness problems.

Alternator Warning Light Test:

2. If other lamps are okay, disconnect alternator 2-pin connector. Hook up SST (or equivalent) as shown. Connect red adapter harness clip to battery positive. Verify that red and green lights illuminate. Start engine and check that both lights go off.
3. If step 2 is not as specified, check for IC regulator, brush, or field coil malfunction.
4. If step 2 is okay, check for alternator warning light circuit malfunction.

WARNING LIGHT STAYS ON

1. Perform VOLTAGE OUTPUT TEST in this section. If okay, check for wiring harness malfunction.
2. If not okay, perform test in step 2 under WARNING LAMP WILL NOT ILLUMINATE.
3. If step 2 under WARNING LAMP WILL NOT ILLUMINATE is okay, turn ignition "ON." Check that voltage at terminal L is 1 - 5V.
4. If terminal L voltage is okay, check for poor connection at battery negative terminal, poor connection between alternator 2-pin connector and battery positive terminal, or stator coil or diodes malfunction.
5. If terminal L voltage is not okay, check IC regulator, field coil, or brush malfunction.

BATTERY OVERCHARGED

1. Turn all electrical loads off and release brake pedal.
2. Check output voltage between terminal S and ground at 2500 - 3000 rpm. If voltage is 14.1 - 14.7V, alternator is okay.
3. If above 14.7V, check for IC regulator malfunction.
4. If below 14.1V, turn ignition "ON" with all electrical loads off and brake pedal released. Check that terminal S reads battery voltage. If okay, check for IC regulator malfunction.
5. If terminal S does not read battery voltage, check for wiring harness malfunction.