Ignition noise when using the auxiliary input to connect an XM radio to your car's audio system is a common problem, and may affect overall sound quality. It can easily be fixed using readily available parts from a consumer electronics store.
Things You'll Need
- Ground loop isolator
- RCA female to 1/8" male cable (3 ft or less)
Determine if the noise you are hearing is ignition noise. Listen for a whine that seems to change as you press the gas pedal and accelerate.
Disconnect the current cable attached to the XM radio's "Line In." Remove the cable completely as it is no longer required.
Locate the car's auxiliary input. It is typically located on the radio itself, in the glove box, or in the center console. You may have already connected the XM radio to this if you chose that method at the time of the original installation.
Unpackage the ground loop isolator. Use the 1/8-inch adapter included with the filter and connect the 1/8-inch end to your car's auxiliary input. Connect the RCA cables (red and white connectors) on one end of the ground loop isolator to the adapter. Hide the ground loop isolator if desired.
Connect the plug of the RCA female to 1/8-inch male cable to the "Line In" jack of your XM radio. Connect the other end of the cable to the free RCA cables on the ground loop isolator. Clean up and arrange the cables as desired.
Turn the car's ignition completely on (the engine must be running). Press the gas pedal several times and listen if the whining noise has disappeared. There should no longer be any noise or the whine should be dramatically reduced if the installation was done correctly.
Tips & Warnings
- If the ground loop isolator did not come with an additional 1/8-inch adapter, purchase one. It should be the shortest possible length, as it is only needed from the isolator itself to the auxiliary input jack of the automobile.
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