Distortion on stereo... possible loose ground, need advice/info...?

Question

Basicaly my headunit on my 97 ford escort produces a helluva lot of distortion the more i turn up the volume, ive tryed using different head units, even the stock one, and the same problem persists. All the wiring seems to be correct with no loose wires or connections i can see. The strange thing is that sometimes i can turn the volume up and its fine, other times its really distorted, sometimes i hit a bump in the road and it works fine untill i hit another... this leads me to believe it may be a loose ground but i have no idea where the stereo ground is located. If anyone has had this problem before or if anyone just knows where i can find the ground points for the stereo i'd be most gratefull...

Cheers

Answer 1

Stereo's are grounded thru the housing of the radio itself,the black wire from behind the radio,and also the antenna wire

Answer 2

the ground has nothing to do with distortion, it sounds like there may be something loose or deteriorating inside of the radio