AM Station Fade Interference

F. AM Station Fade - Interference

Poor AM radio reception on weak stations, fading, noise, or interference due to the following:

1. Ignition Noise

2. Windshield Wiper "Pop"

3. Windshield Wiper (Electric Motor Static)

4. Brake "Pop"

5. Heated Windshield

6. Windshield Washer Motor Noise

7. Turn Signal.


Perform the following to verify the noise concern.

1. Ignition Noise:

^ Start engine.

^ Tune to a weak AM radio station.

^ Increase the engine RPM.

^ Ignition noise is a regular/periodic "tick" or "pop" and frequency changes with RPM. (Charging system noise is a smoother, higher pitched whine.)

2. Windshield Wiper "Pop":

^ Engine not running.

^ Tune in a weak AM radio station.

^ Activate the windshield wiper.

^ The "pop" accompanies start or finish of a wiper cycle.

3. Windshield Wiper (Electric Motor Static):

^ Engine not running.

^ Tune to a weak AM radio station.

^ Activate the windshield wiper.

^ The "hash" or other noise is heard as the wiper moves.

4. Brake "Pop":

^ Engine not running.

^ Tune in a weak AM radio station.

^ Depress the brake pedal.

^ The "pop" occurs when the brake light is activated.

5. Heated Windshield Interference:

^ Refer to TSB 91-16-9.

6. Windshield Washer Motor Noise:
^ Engine not running.

^ Tune in a weak AM radio station.

^ A "buzz" or "hash" is heard when the windshield washer is activated.

7. Turn Signal:

^ Engine not running.

^ Tune in a weak AM radio station.

^ A noise is heard when a turn signal is activated.


RADIO NOISE ISSUES - SERVICE PROCEDURE

Perform ALL of the following actions to service radio noise issues.

1. Inspect the antenna cable connections for signs of damage or corrosion.

2. If the antenna connector is corroded, replace the antenna.

3. Check for possible water leaks or holes where water can enter from road splash. If found, seal holes where water entry is found.

4. Fill the antenna female connector with grease (F2AZ-19584-A).

5. Install the one piece, double shielded antenna cable (F1VY-18812-A).

a. Route the cable down the left hand side of the vehicle from the radio to the antenna, beneath the carpeting. The original cable may have been routed down the right side of the vehicle.

b. Secure cable with tape as needed to prevent possible rattles.

6. Apply grease (F2AZ-19584-A) to the outside of the installed antenna cable connector at the antenna. This will prevent water entry into the antenna cable connector shell.