Originally Posted by
MKader17
The whine is likely cause by a bad ground.
Chevys actually have a pretty wimpy ground for the head unit from factory. Its something that's easy to fix and even if it doesn't solve the problem it may help you later.
Best bet though is your amp ground. The best way to run it is a bolt through the floor (like pictured above), but on the other side you should add another wire that connects to the frame. Then, at the front of the truck run another wire from the frame to the negative battery terminal.
If all that's good, you alt may be going bad.
By the way. Running Power wire and RCA's near each other does nothing. My power wire and RCA's are directly next to each other with zero problems.