Diagnostic Routine F

Diagnostic Routine F

Diagnostic Overview

The Generator is Noisy

Normal Operation and Fault Conditions

The generator is belt-driven by the engine accessory drive system. There are several sources of generator noise which include bearing noise, electrical fault noise, generator or belt pulley misalignment. A generator with certain types of diode or stator failures can also produce an audible noise.

Visual Inspection and Diagnostic Pre-checks

- Inspect the FEAD (Front End Accessory Drive) belt.

- Inspect for loose bolts/brackets.

- Inspect the generator/pulley.

Pinpoint Test

1. CHECK FOR ACCESSORY DRIVE BELT NOISE AND LOOSE MOUNTING BRACKETS

1. Ignition OFF.

2. Check the accessory drive belt and tensioner for damage and correct installation. REFER to Accessory Drive Belt or REFER to Accessory Drive Belt Tensioner .

3. Check the accessory mounting brackets and generator pulley for looseness or misalignment.

Is the accessory drive OK?






2. CHECK THE GENERATOR MOUNTING

1. Check the generator mounting for loose bolts or misalignment.

Is the generator mounted correctly?






3. CHECK THE GENERATOR FOR NOISE

1. 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?