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Tahoe / Yukon Service Manual

Generator Noise Diagnosis

Diagnostic Instructions Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Review Strategy Based Diagnosis for an overview of the diagnostic approach. Diagnostic Procedure Instructions provides an overview of each diagnostic category. Diagnostic Aids Noise from a generator may be due to electrical or mechanical noise. Electrical noise or magnetic whine usually varies with the electrical load placed on the generator and is a normal operating characteristic of all generators. When diagnosing a noisy generator, it is important to remember that loose or misaligned components around the generator may transmit the noise into the passenger compartment and that replacing the generator may not solve the problem. Drive Belt Chirping, Squeal, and Whine Diagnosis Drive Belt Rumbling and Vibration Diagnosis Drive Belt Tensioner Diagnosis Circuit/System Testing

  1. Start the engine. Verify the noise can be heard. Compare the concern to a similar vehicle.
  2. Perform a charging system test. Verify that the generator is charging properly.
  3. Inspect the generator, generator mounting, wiring harness, heater hoses, A/C lines, or other accessory equipment that may be incorrectly routed or be the cause of noise being transmitted into the passenger compartment.
  4. Ignition OFF, remove the engine drive belt.
  5. Verify the generator, A/C compressor, water pump pulley, power steering pump, idler pulley, and tensioner pulley spin freely. ⇒ If any of the pulleys do not spin freely Replace the affected component. ⇓ If all belt driven components spin freely
  6. Start the engine. Operate the engine for no longer than 30-40 seconds.
  7. Verify that the noise is no longer present. ⇒ If the noise is still present The generator is not the cause of the noise. Refer to Symptoms - Engine Mechanical ⇓ If noise is no longer present
  8. Inspect for worn accessory drive components or abnormalities such as severe cracking, bumps, or missing areas in the accessory drive belt and/or misalignment of system components Repair Instructions Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Accessory Drive Primary Belt Replacement for 3.0L (LM2) Belt Idler Pulley Replacement for 3.0L (LM2) Drive Belt Tensioner Replacement for 3.0L (LM2) Accessory Drive Primary Belt Replacement for 5.3L (L82/L84) or 6.2 (L87) Accessory Drive Auxiliary Belt Replacement for 5.3L (L82/L84) or 6.2 (L87) Belt Idler Pulley Replacement for 5.3L (L82/L84) or 6.2 (L87) Generator Replacement