I know this is an old thread, but I had the same buzzing from aftermarket LED headlights. Nice lights but destroyed the sound system until I installed these on the wire just behind the headlight. I do have the rectangular "work truck" headlights so it was inexpensive and easy. Under $10 at Amazon: Ferrite Ring Core Black RFI EMI Noise Suppressor Cable Clip-20Pcs
Was your buzzing sound coming through the speakers only when listening to am/fm? I tried adding ferrite beads on my headlight wiring, but it didn't make an appreciable change in sound, changing to an aftermarket head unit (which I was doing anyway) somehow did the trick though!
My headlights (only when on low beam, no problem on high beam) still cause interference/squealing through the speaker of our handheld vhf/uhf race radios though.
At least I've got my tunes back, so I can live with that!
2008 Ford E350 Extended
Linear Mode
