Noise in your car audio system can be caused by more than one issue. Noise can be static, whine, hiss, distortion, or other sound issues.
Follow the steps below to locate and fix the source of the noise:
- Make sure to check ground wires.
- Check the ground wires to all of the components in your system. This may include the receiver (head unit), external amplifier, equalizers, or other components. All components in your audio system should have a ground wire attached firmly to bare metal on the car. In addition, the ground wire should be as short as possible. Long ground wires can pick up noise that can be heard in the audio system. If you have extended the ground wire, make sure the splice is firmly connected and you may need to use a larger gauge (thicker) ground wire.
- Perform the steps below if you have external amplifier:
- Turn on your audio system without the car running. Put in a CD and set the CD player on pause, or insert a blank tape if you have a cassette deck. Turn up the volume to a normal listing level. If you hear a hissing sound, turn down the gain on the amplifier and turn up the volume on the receiver. Adjust these two settings to minimize the hiss.
- Make sure the patch cables between the amplifier and the receiver are not running near other power wires (including the wire providing power to the amplifier). If necessary, reroute the cables away from other wires. Make sure you are using high-quality patch cables.
- On year 2000 model and newer car stereo receivers, verify that the amplifier is connected to the AMP REMOTE lead on the car stereo, if available.
- If whine or clicking noise is heard.
- If you hear a whine or clicking noise that changes with the speed of the engine you may have a problem with the electrical system of the car. This can be caused by old spark plugs and wires, ignition system components, or by a problem with the alternator. If your car has not been tuned up recently your mechanic may be able to resolve the issue by checking these components and systems. If these items are checked and are not the issue then you may need to install a noise suppressor to help eliminate the noise.
- Noise is heard only when listening to the radio.
- If the noise is only heard when listening to the radio, it may be coming through the antenna. Remove the antenna wire from the receiver. If the noise goes away you may need to install an antenna noise suppressor that plugs in between your antenna and the receiver.
- Noise is heard from other sources.
- Turn other components in the car on and off to see if the noise changes or goes away. Other systems such as air conditioning, navigation systems, lights, turn signals, cell phones, and other components can cause noise in the audio system. If any of these is causing the noise, you may need to reroute the wires in the back of the receiver to move them away from the source of the noise.
- Make sure to check connections between components.
- Check the connections between each component in the system and to the speakers. Make sure all connections and any wire splices are secure.
- Make sure to check each speaker.
- Check each speaker individually by using the balance and fader controls. If only one speaker is causing the noise and it is a buzzing or distorted sound make sure there is nothing pressed up against the speaker. If only one speaker is the problem, the speaker may need to be replaced.
NOTE: If noise suppressors are needed, check with your dealer or installer for recommendations on appropriate parts to purchase and install.
The troubleshooting steps listed above should resolve your issue. If you have completed all of the steps and the issue is not resolved, service may be required.  Go to Product Repair.