Hum Or Buzz Noise From Audio Speakers At Start Up - keywords amp bose chime left light noise radio right seatbelt speaker

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Some customers may comment of a noise that is heard from the vehicles audio speakers. This noise occurs on start up prior to the seatbelt becoming latched. This noise is a momentary hum or buzz that occurs 2 or 3 seconds after starting the engine. The noise can be heard in all of the radio speaker channels. If the driver's seat belt is buckled so the seat belt chime is off, the noise will not occur. This noise is induced by the voltage regulator inside of the alternator.

To determine that this is the noise, unplug the connector from the alternator. If the noise is eliminated, this noise is a normal characteristic of vehicles equipped with US8 and US9 Radios. No repairs are recommended.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.