hey i know there is heaps of posts on this already but i still cant seem to stop the problem

My radio is crystal clear when my car is off but when i turn my engine on it goes anoyingly fuzzy only on one channel (triple m) it is anoying the hell out of me and i wanna solve it.

im running a 4 channel amp and the rca's and power cable are down different sides of the car and they dont cross anywhere. i was wondering could it be the power cable intervering with the antenna cable or interverence with the powercable in the engine bay or something else?

any help would be great