Ground Loop Problem
 

So once again I think I have a ground loop problem. When I have the radio on but at volume 0, I can hear engine noise in my speakers. I have the power rem and ground from the head unit running on the passenger side and the signals running down the drivers side. I read that it is better to ground the head unit to the same place that the amp is being grounded so i ran a wire to do so. I decided to ground the main amp terminal to the bolt in the trunk that runs under the bar that runs across the car. I believe it the bolt here is suppose to be used for securing things down. It has a black plate attached to it that comes out from the carpeted mat (please forgive my descriptions). I am running 0/1 guage wire for the power. And I have upgraded the ground going to the batter to 0/1 guage wire as well. In the front dash I have the Peswiac ground, steering wheel ground, and head unit ground all going to one wire that goes to the amp ground that I described above. If anyone has any ideas how i might be getting this noise I would appreciate any feed back. The engine noise is not too significant, but it is there. I would say that I cannot hear it at volume level 3 on my kenwood ddx714.

Cut the ground from the head unit that runs to the back and ground it behind the dash. Then try this with the car running, disconnect the rca's from the amp to see the noise is coming from rca or the amp itself. And get back to me. or post up here! lol

Thanks Jeff this makes sense for trouble shooting. Where would you recommend grounding it behind the dash?

Distance RCA cables from power and speaker lines.

I clean the paint off a 1 inch area to expose a good clean ground just in front of the shifter under the radio. But anywhere will do! close to radio as possible!

Thanks Jeff I will try this. Would it really make a difference if my RCAs are running next to the speaker wire going to my front right speakers? If so I was thinking i could probably run the RCAs right down the middle of the car. I will try regrounding and unplugging the RCAs to see if that could be the problem.