Speaker buzz

[Mikey]

I finally got out for the first time this season. Various reasons for the later start. Boat was all good except for one small issue. Speaker BUZZ when motor on and boat in gear.

With just stereo on or motor running ,with stereo everything is fine....Put the boat in gear with motor running and theres a high pitched Buzz.

I,m wondereing when i dewinterized and rehooked batteries etc did i miss something or likely a ground wire loose etc. Any suggestions as to where to look first. All of this is having Ipod hooked up to USB port, although i don't think this should matter.

Any thoughts and or suggestions?

[Beejwest]

Sounds like a ground issue. I had the same issue with noise in my tower speakers after installing an ACR for a twin Batt setup. I changed the ground on my HU to my starting battery and it eliminated 99% of the noise. Grounding issues are (from what I understand) the most common culprit for noise in a boat.