I just finished installing a Garmin 665 on my Ultra. It now causes feedback on the left side only when on Aux. Any ideas on what the cause may be?

 

There's no way it's feedback. For it to be feedback, the zumo would have to be picking up the sound from the speaker and amplifying it.

I would put some dielectric grease on all of the connections and see if that fixes it. If you take the zumo and plug computer speakers into it and it sounds good. chances are it's connections.

Good luck

 

Ok thanks I will give it a try.

 

Found it. The audio cable I have isn't adequate. Thanks for getting me going in the right direction.