Buzzing speaker after headlight bulb change

2009 Subaru Outback. I changed all 4 headlight bulbs (H7 for low beam and 9005 for high beam) and now when I turn the low beams on there is a buzzing noise from the right-hand door speaker. Causal link or coincidence?

If I may quote Leroy Jethro Gibbs, “There is no such thing as a coincidence”.

No link between the two. Stuff happens.

Are these LED or HID type bulbs or regular halogen?

You can get the bulbs out, maybe even one by one and see if the noise disappears.

Easier than taking them out: with radio playing, unplug them one at a time.

Did you keep halogens or did you switch them to leds or hid ? If you changed then yes it could be one of the new bulbs . A lot of those are NOT just plug and play despite what they say specially if you got cheap ones .

These are the same type of bulbs that were in there before, just halogen. Update: the issue seems to be limited to the AUX setting with the audio cable connected to the outlet in the center console. If I unplug the cable the noise ceases. The FM setting works fine. OEM radio.

Try a new audio cable .


There’s usually a wire from each light fixture that connects to the chassis in that area. Make sure all of those are making a good connection, clean all corrosion, etc.

The unterminated AUX cable is acting as an antenna and picking local electrical noise which then gets amplified by the AUX input circuit. Keep the cord unplugged unless you are using it.


Nailed it, Cougar. With the IPod attached the noise disappears. Thanks for the insight.

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You’re welcome for the help. Unterminated input lines can cause strange STUFF to happen. With the iPod connected you then have some resistance and shielding to reduce and block the noise input to the AUX circuit.