Buzz, Hum, or Other Noise Interference through Radio AUX Input when Using MP3 or Other Audio Playing Equipment

Some customers may comment on a buzz, hum, or other interference when using an MP3 player or other types of audio equipment that is input through the radio AUX jack. This condition may only be present when the audio device is being powered from the vehicles 12 Volt power outlet (Cigar Lighter).

Some portable audio equipment may be susceptible to certain types of electronic noise present in the vehicles 12V power outlet. In most cases the reported noise source is from the heated/cooled seat module. The seat controller is Pulse Width Modulated, and some audio equipment may pick up that noise.

If you experience this type of interference here are three ways to eliminate it:

1. DO NOT turn on the heating or cooling features of the front seats while using the audio player.
2. If the audio device is capable of being self powered (battery) use it that way instead of being plugged into the vehicles power outlet.
3. Have the customer purchase a Ground Loop Isolator such as *Radio Shack Catalog #270-054. This device plugs in between the radio and the customer's audio device. It is packed with one included Y-Adapter. If purchasing the *Radio Shack product, you will require an additional Y-Adapter Catalog #274-369. This device should be installed between the audio player and the AUX input of the vehicle radio. These catalog numbers are stocked nationally at *Radio Shack Retail Stores and are currently available. Other similar products are available through other electronics or car stereo retailers defined as Ground Loop Isolators.

Parts are currently available in the U.S. nationally through *Radio Shack retail locations or at through the mail at Radio Shack direct ordering 1-800-843-7422. In Canada, parts are available nationally through *The Source By Circuit City retail locations or at www.thesourcecc.com.

*We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources.