Pinpoint Test F: The Generator is Noisy

Pinpoint Test






Pinpoint Test F: The Generator is Noisy

Refer to Wiring Diagram Set 12, Charging System for schematic and connector information. Diagrams By Number

Normal Operation

The generator is belt-driven by the engine accessory drive system. There are 2 sources of generator noise: bearing noise and electrical fault noise. A generator with certain types of diode or stator failures may also produce an audible noise.

This pinpoint test is intended to diagnose the following:
- Accessory drive belt
- Loose bolts/brackets
- Generator/pulley



PINPOINT TEST F: THE GENERATOR IS NOISY

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F1 CHECK FOR ACCESSORY DRIVE BELT NOISE AND LOOSE MOUNTING BRACKETS


- Ignition OFF.
- Check the accessory drive belt and tensioner for damage and correct installation. Refer to Drive Belts, Mounts, Brackets and Accessories.
- Check the accessory mounting brackets and generator pulley for looseness or misalignment.
- Is the accessory drive OK?

Yes
GO to F2.

No
REPAIR as necessary. TEST the system for normal operation.

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F2 CHECK THE GENERATOR MOUNTING


- Check the generator mounting for loose bolts or misalignment.
- Is the generator mounted correctly?

Yes
GO to F3.

No
REPAIR as necessary. TEST the system for normal operation.

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F3 CHECK THE GENERATOR FOR MECHANICAL NOISE


- With the engine running, use a stethoscope or equivalent listening device to probe the generator and the accessory drive area for unusual mechanical noise.
- Is the generator the noise source?

Yes
INSTALL a new generator. REFER to the Generator Service and Repair procedure.

No
REFER to Engine to diagnose the source of the engine noise. Testing and Inspection

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