Diagnosis/Service Procedure

Diagnosis

Verify the condition with the vehicle outdoors and away from any buildings or overhead electrical lines.

1. With the hood closed, turn ignition switch to the "Accessory" position.

2. With the radio set on the "AM" band and normal volume, verify that no interference is present while the wipers are turned "Off".

^ If interference IS present, it is originating from a source other than the wiper system. See the Service Manual for additional diagnosis.

^ If NO interference is present, turn the wiper switch to the low or high position. It interference IS present when the wiper arms are moving, turn the wiper switch to the off position. If the interference stops when the wiper arms "park" or stop moving, three additional ground wire circuits are required.

3. With the transmission in park and the parking brake set, start the engine and allow to idle.

^ If interference IS present, slightly increase the engine RPM's. If the noise speeds up with the increase in engine speed and then slows down when the engine is allowed to return to idle, three additional ground wire circuits are required.

^ If NO interference is present, see the Service Manual for additional diagnosis.

Service Procedure

1. Record radio station presets.

2. Disconnect negative battery cable.