I have a pioneer deh-p700bt. Ive been having a few issues with my system so I took my head unit in for warranty work. After getting it back and the people saying there was nothing wrong with it, i reinstalled it and continued to have ground noise. I thought I had figured it out, but didn't. In short, I got fed up with it and ran some cheap speakers directly to the HU. You'd figure it would be all good right? Im not getting any sound. It worked with the car off. I took it for a drive and all of a sudden, no sound. I turned it off, then back on and it worked. Hit a bump and it hasn't worked since. Any ideas?