I am having a hell of a time finding a proper ground for my amp. I always have a high pitched wine. I have used the seat belt bolts under the seat, the shock tower, the bolts on the floor of the trunck towards the rear, and added a bolt to the side by the shock where there was already a bolt hole. none of these work. I am getting pissed. I tried to drill a new hole too by the spare tire but there are two layers of metal separated by about 1/2 inch. any ideas? and yes I scraped the paint away to reveal bare metal.

 

I think this may be the wrong forum for your question but at any rate here's your answer...

Any of the grounds you mentioned will work fine but I think you are missing one key step. You need to take a wire brush, wire wheel, or some sandpaper and expose some bare metal around the surface of the bolt where you are grounding to. You must remove all paint in order to expose bare metal so that you get a good and proper ground.

 

there must be something wrong with your amp then, cuz all the places you mentioned are good. try getting a inline noise filter..

 

i drilled a hole in the metal, put a screw and it worked

 

That is weird b/c it does it with my MTX amp and my brand new soundstream. and yes, i exposed bare metal for the grounds. maybe it is the amps.

 

get a ground loop isolator to get rid of noise..