Chart 17

Diagnostic Chart 17:

BACKWAY NOISE
Noise that enters the audio component through its wiring harness is most commonly detected in power and ground circuits. (Noise that can be heard at minimum volume and not frontway or sideway noise.)

SOME CAUSES:
^ Poor grounding of the radio or of unsuppressed electrical components.
^ Poorly routed wires.
^ Defective suppression of electrical components.

SOLUTIONS:
^ Suppression (capacitors, etc.) preferably can be installed at the noise source, then at the radio, or both.
^ Switch pops are backway noise and are best suppressed using capacitors.
^ Squeals and buzzes are best suppressed using filter or generator whine packages.
^ Check ground strap (see "Ground Strap Check").

IMPORTANT: Before proceeding:
^ Service any known driveability problems.
^ Check for any technical service bulletins on this type of radio noise.