Right rear speaker on my riding partner's 01 Ultra has a terrible buzz..It also has a Harley amplifier under the trunk.Would an amplifier problem cause this? It seems to increase with the engine speed, and is non-existent with the engine not running.a different speaker makes no difference.

Thanks in advance

Mark

 

Sounds like a ground issue. Check the wires and see if one is frayed and touching the frame somewhere.

 

Same thing happened w/ mine and it was the amp.

 

Either Alternator or Spark Plug noise I'd say......
See if it changes tone when you load/unload the charging system. Turn everything electrical on that you can at once for most load you can get, brakes on, headlight HI, 4 way flashers on, see if it changes sound. If so, I'd say Alternator noise.
Check plug wires for cracks, loose connection, dry, burnt boot. Moving the wires around and see if that changes anything. Plug/unplug them....
Good luck......
Or, could be the amp or radio output.
Will take some trouble shooting to figure out for sure.
Has he changed plugs recently? Or anything else that might have caused it?

 

Thanks, Now to find an amp!!

 

Thanks, Doesn't seem to matter what is on or off. If all the speakers were doing it I would be less suspect of the sound system itself.

MArk