[caniborrow50cnts]

I have confirmed there are no loose grounds in the engine. Also, there are no issues with the speaker system. I took another battery and connected the amp and radio to it directly, started the car, no noise. I cannot find any melted wires. I pulled every fuse/relay I could, to see if any of them broke the circuit creating the sound. I am a couple of days away from swapping every sensor with my other eclipse. nothing obvious is helping. The only thing that would make sense is a wire voltage changes with the engine. I will bolt another ground wire to the block to see if it makes a change though. A bigger ground wire should pull more electric. Path of least resistance right?