Alternator: Testing and Inspection

To avoid generator damage, always follow precautions shown below.

CAUTION:
- Do not mistake polarities of IG terminal and L terminal.
- Do not create a short circuit between IG and L terminals. Always connect these terminals through a lamp.
- Do not connect any load between L and E.
- When connecting a charger or a booster battery to vehicle battery, refer to battery charging.

Trouble in charging system will show up as one or more of following conditions:
1. Faulty indicator lamp operation.
2. An undercharged battery as evidences by slow cranking or indicator clear with red dot.
3. An overcharged battery as evidenced by excessive spewing of electrolyte from vents.

Noise from generator may be caused by a loose drive pulley, loose mounting bolts, worn or dirty bearings, defective diode, or defective stator.

Faulty Indicator Lamp Operation:

UNDERCHARGED BATTERY
To check generator when battery is undercharged, use following procedure.




1. Connect voltmeter and ammeter as shown in left figure.

NOTE: Use fully charged battery.




2. Run engine from idling up to 2,000 rpm and read meters.






NOTE:
- Turn off switches of all accessories (wiper, heater etc.).
- Consideration should be taken that voltage will differ somewhat with regulator case temperature as shown in left figure.

3. If voltage is higher that standard value, check ground of brush. If brush ground is correct, replace IC regulator.
4. If voltage is in standard value, run engine at 2,000 rpm and turn on head light and heater motor.
Measure current and if less than 20 A, repair generator.

OVERCHARGED BATTERY
To check generator when battery is overcharged, use following procedure.
1. With engine running at 2,000 rpm, measure voltage.
2. If measured voltage is out out of standard value, check brush ground or IC regulator.

CONDENSER




Check condenser capacity.
Condenser capacity: 0.5 micro F