Generator Whine Concerns

INSPECT:
- Check the ground terminal on the battery.
- Check for coated mounting bolts on the generator bracket.
- Check for a faulty mounting of the generator to the engine.
- Make sure all ground straps between the engine and the frame are clean and tight.
- Try the following fixes:
1. If noise is still present, check the charging system.Starting and Charging System.
2. If the charging system is functioning normally, check for technical service bulletins on generator whine.
3. Install a filter GM P/N 1224205 in the battery feed to the radio.
4. Try installing the filter with the following variations if noise is not eliminated.
- Install the filter with the single wire side toward the radio and the ground wire attached to a good ground.
- Remove the ground to the filter.
- Reverse the filter so the two wire side is toward the radio with the ground wire attached to a good ground.
- Remove the ground from the filter.
5. If noise is still present, install another filter GM P/N 1224205 in the ignition feed to the radio. Install using the same variations as the first filter. If the installation of this filter causes turn "ON" or turn OFF delays or other noticeable performance concerns, remove it and install a 0.47 mF capacitor to ground in its place.
6. Remove any unneeded filters after Repair, before reassembling the vehicle.

RADIO NOISE:
A noise "sniffer" may be used to aid in troubleshooting Radio noise, see Antenna System Test. System Test - Antenna
1. Test the Radio outside with the hood down.
2. Ignition noise on FM indicates a possible defective Electronic Ignition (E1) System. Refer to Ignition System. Ignition System
3. Check Antenna coax connectors for corrosion or bad connections.
4. If a test Antenna is used, ground the base of the Antenna to the vehicle body.
5. Coated screws or bolts can act as poor grounds.

GENERAL:
- Check for a broken (or partially broken) wire inside of the insulation which could cause system malfunction but prove "GOOD" in a continuity/voltage check with a system disconnected .These circuits may be intermittent or resistive when loaded, and if possible, should be checked by monitoring for a voltage drop with the system operational (under load).
- Check for proper installation of aftermarket electronic equipment which may affect the integrity of other systems (see Troubleshooting Procedures). Diagnostic Aids
- Refer to System Diagnosis.