Noise Diagnosis - Radio Noise

A noise sniffer may be used to aid in troubleshooting radio noise.
1. Check radio reception in an area away from tall buildings, metal structures, power lines, fluorescent lighting and power tools.
2. Ignition noise on FM indicates a possible defective Electronic Ignition (EI) System. Refer to Engine Controls. Powertrain Management
3. Check antenna coax connectors for corrosion or bad connections.
4. If a test antenna is used, ground the base of the test antenna to the vehicle body.
5 Coated screws or bolts can act as a poor ground.

NOTE TO TECHNICIANS: Electromagnetic Interference (EMI) can cause a fewer number of stations to be received in one of the three modes. The EMI can be caused by various vehicle components. This may be the cause of the differences in reception. Check for components powered up in the three various key positions. This may eliminate engine running components, ignition on components, etc. For example, if the same number of stations are received with the engine running as when the engine was off, the components active with the engine running are not causing the interference.
^ Determine type of audio complaint.
^ Try to duplicate condition (listen to AM or FM, start vehicle, put in a good CD or cassette).