Defective HU or Amp?

geepherder wrote: All great advice. How is your amp getting signal, are you using high quality line out converters, or are you using the high level inputs built into the amp (assuming it has them)?  If you're using high level inputs, I'd recommend using a line output converter instead- using high level inputs can sometimes also give the symptoms you are describing.

oh,yeah. when i had it in the other vehicle the hu was an aftermarket with three sets of preamps, could this be the whole problem?

That makes a huge difference, indeed.  I bet you didn't adjust any of the controls on the amp when you transplanted the gear into your current vehicle, right?  Do a search (upper right hand of the screen) in here on setting gain, and read up.  Also, I'm not a huge fan of using an amp's high level inputs.  You're much better off using a good line-out converter, which will give you rca outputs.My ex once told me I have a perfect face for radio.

I have adjusted the controls, I will read up on gain, and l will probably get an aftermarket stereo soon, will check out crutchfield for research on HUs with three preamps