Initial Inspection and Diagnostic Overview

1. Test Radio outside of building with hood down.
2. Most noise can be found on weak AM stations near the low frequency end of the band.
3. Ignition noise on FM indicates a possible defective HEI system.
4. If a test antenna is used, ground the base of the test antenna to the vehicle frame. DO NOT hold that mast of the antenna.
5. Coated screws or bolts can act as a poor ground. Make sure grounds G201 and G202 are clean and tight.
6. Most hoses are conductive unless they have a white stripe.
7. When shielding components, use aluminum foil tape and ground BOTH ends of the shield.
8. Any noise is best corrected by suppression at the source of the noise.
9. Power lines, bridges, buildings, etc., can block AM reception.
10. FM reception can be affected by atmospheric conditions, terrain, large buildings and the strength of the transmitter.

^ Check for a broken (or partially broken) wire inside of the insulation which could cause system failure but prove "GOOD" in a continuity/voltage check.
^ Check for proper installation of aftermarket electronic equipment which may affect the integrity of other systems.