Hi sorry if this is a duplicate, maybe you can point me in the right direction if this has been answered before. I have a 04 with the bose. Swapped the head unit and when the engines turned off it works/sounds great. As soon as i turn the engine on it makes a terrible high pitched whine noise. It does NOT go up and down with the engine. Sometimes after driving for a while it will go away, sometimes not. Re-grounded it and it didnt help at all. Any suggestions would be really appreciated as its driving me insane