Symptom Related Diagnostic Procedures

TROUBLESHOOTING HINTS
1. Charging warning light does not come on when the ignition switch is turned to "ON" position, before the engine starts.
- Check the bulb.

2. Charging warning light does not switch off after the engine starts.
- Check the IC voltage regulator inside the generator

3. Discharged or overcharged battery.
- Check the IC voltage regulator inside the generator.

4. The charging warning light illuminates dimly.
- Check the diode (inside the combination meter or generator) for a short-circuit.

TROUBLESHOOTING GUIDE
The charging system troubleshooting guide is shown in the following steps.

STEP 1.

Q: Is the battery in good condition? (Refer to Battery - On-vehicle Service - Battery Check.)

YES: Go to Step 2.
NO: Charge or replace the battery.

STEP 2.

Q: Is the generator drive belt in good condition? (Refer to Maintenance Service - Drive Belts.)

YES: Go to Step 3.
NO: Adjust the belt tension or replace the belt.

STEP 3.

Q: Does the charging system warning light turn on brightly when the ignition switch is turned to the "ON" position?

YES: Go to Step 4.

NO: Check the ignition switch. (Refer to Ignition switch - Inspection.)
Check for burnt-out charging system warning light bulb.
Check the generator. (Refer to Generator - Disassembly and assembly - Inspection.)
Check the charging system warning light-related circuits.

STEP 4.

Q: Does the charging warning light go out after starting the engine?

YES: Go to Step 5.
NO: Check the generator (Refer to Generator - Disassembly and assembly - Inspection.)

STEP 5.

Q: Is an oscilloscope available?

YES: Go to Step 6.
NO: Go to Step 7.

STEP 6.

Q: Does the oscilloscope show a normal wave pattern? (Refer to Charging system - Wave pattern check using a oscilloscope.)

YES: Go to Step 7.
NO: Check the generator. (Refer to Generator - Disassembly and assembly - Inspection.)

STEP 7.

- Engine: 2,500 r/min
- Headlight: ON (high beam)
- Voltage between generator "B" terminal and the positive battery terminal
OK: 0.5 V or less
- Voltage between the negative battery terminal and generator body
OK: 0.5 V or less

Q: Are the generator output line and ground line in good condition?

YES: Go to Step 8.

NO: Check the generator output line.
Check the generator ground line.

STEP 8.

Q: Is the output current normal? (Refer to Charging system - On vehicle service - Output current test.)

YES: Go to Step 9.
NO: Check the generator (Refer to Generator - Disassembly and assembly - Inspection.)

STEP 9.

Q: Is the regulated voltage normal? (Refer to Charging system - On vehicle service - Regulated voltage test.)

YES: Go to Step.
NO: Check the generator (Refer to Generator - Disassembly and assembly - Inspection.)

STEP 10.

Q: Are the voltage drops in the generator output line normal? (Refer to Charging system - On vehicle service - Generator output line voltage drop test.)

YES: Generator is normal. Check other systems.
NO: Check the output line.