Test A: Battery Is Discharged Or Voltage Is Low

Check battery. See BATTERY LOAD TEST under ON-VEHICLE TESTING. If battery is okay, go to next step. If battery is discharged or faulty, charge or replace as necessary.
Check generator output. See GENERATOR LOAD TEST and GENERATOR NO-LOAD TEST under ON-VEHICLE TESTING. If generator output is okay, go to next step. If generator output is faulty, repair wiring or replace generator as necessary.
Check for parasitic loads. See PARASITIC DRAW TEST and ELECTRONIC MODULE PARASITIC DRAW TEST under ON-VEHICLE TESTING. If no problem is found, go to TEST B: WARNING INDICATOR ON, SYSTEM IS NOT CHARGING . If any problem is found, diagnose and repair wiring or components as necessary.