About a year ago, I modified my 2011 CVO radio accessory to come directly from the GPS harness (where my audio library sits on my Garmin) under the fairing per help in this forum. At the same time I added a Boostaroo to get better volume from the audio files on the Garmin. I've recently noticed (though it may have been there all along--I usually listen to XM), an electronic whine whenever I'm playing from my Garmin audio library. I presume its engine noise since it isn't present with the engine not running and when the engine is running, the frequency of the whine increases/decreases proportionally to engine speed. Has anyone else seen this? Are there filters I could install to avoid this noise (I recall doing the same in a car stereo years ago to remove alternator noise)?
Thanks for any and all tips.