For 1990-2009 cars

### Diagnosis

• | Noise from a generator may be caused by a loose drive pulley, loose mounting bolts, worn or dirty bearings, defective diode or defective stator. Refer to Starting and Charging Schematics .

• | For diagnosis of the PCM controlled generator, refer to Powertrain Control Module Controlled Generator Diagnosis .

| Caution: Before removing or installing any electrical unit, or when a tool or equipment could easily come in contact with "live" or "hot all the times" exposed electrical terminals, disconnect the negative battery cable to help prevent personal injury and/or damage to the vehicle or components. Unless instructed otherwise, the ignition switch must be in the OFF or LOCK position.

• | In order to avoid damage to electrical equipment, always observe the following precautions:

• | Do not reverse the connections to the generator.

• | Do not short across or ground any of the terminals in the charging circuit, accept as instructed by the instructions.

• | Never operate the generator with the output terminal disconnected.

• | Before connecting a charger or a booster battery to the vehicle battery. Refer to Jump Starting in Case of Emergency .

• | Trouble in the charging system will show up as one or more of the following conditions:

• | A faulty indicator lamp operation. Some vehicles have a voltmeter instead of an indicator lamp. The needle on the voltmeter indicates system voltage.

• | The needle stays at either end of the gage, indicating that there may be a defect in the charging system.

• | An undercharged battery, as shown by slow cranking or a dark hydrometer in the battery.

• | An overcharged battery, as shown by leaking electrolyte from the vents.