Aurora V8-4.0L VIN C (1996)
Alternator: Component Tests and General Diagnostics
Noise from a generator may be caused by a loose drive pulley, loose mounting bolts, worn or dirty bearings, defective diode, or defective stator. A high
frequency whine or magnetic noise may he heard at full output and is normal.
An output test as described in the "Generator Functional Check" should be performed to help distinguish bearing noise from magnetic noise (also
called whine). A shorted bridge diode will reduce output by 1/3 of the rating and have a "growling" noise when at high load. It is also helpful to listen to
the generator with a moderate load (engine cooling fans or headlights ON) to determine if there is a being or magnetic noise.
To avoid damage to the electrical equipment, always observe the following precautions:
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Do not reverse connections to the generator.
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Do not short across or ground any of the terminals in the charging circuit except as directed by the service manual.
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Do not apply battery voltage directly to the regulator "L" terminal for testing. A 400-500 ohm resistor must he used.
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NEVER disconnect battery cables from the output terminal or battery while the generator is operating.
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When connecting a charger or booster battery to the car battery, refer to Battery. See: Battery
Trouble in the Charging System will show-up as one or more of the following conditions:
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"AMP indicator (if equipped) either does not light with ignition switch in the "ON" position (before engine start) or does not go out after engine
start. Driver Information Center (DIC), if equipped, displays "CHECK CHARGING SYSTEM."
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"SERVICE ENGINE SOON."
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An undercharged battery as evidenced by slow cranking or dark hydrometer, refer to Battery.
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An overcharged battery as evidenced by spewing of electrolyte from the vents.
If an undercharged or overcharged battery condition occurs, the following procedure may be used to diagnose the charging system. Remember that an
undercharged battery is often caused by accessories being left on overnight or by a faulty switch which allows a lamp (such as a trunk or glove box lamp)
to stay 'ON." Refer to "Parasitic Draw Test". See: Testing and Inspection
1. VISUAL CHECKS: All generator diagnosis should begin with a visual inspection. Visual inspection should include checking the serpentine belt
for damage or looseness. Check for proper belt tension with belt tension gage J 23600. Inspect all charging circuit electrical connections for
damage or looseness.
2. PERFORM GENERATOR FUNCTIONAL CHECK: Perform the "GENERATOR FUNCTIONAL CHECK" trouble tree. This generator
does not have a test hole. See: Initial Inspection and Diagnostic Overview
