didnt have ground now I do?

Hi wonderful forumn that has helped me out so much. ok I think I have read all 800 posts of grounding issues. I finally learned how to use a DMM to figure out where to ground my apms.

So I have a 2006 shrysler 300, for headunit it is a pioneer avic n2 2 amps power acoustik 4 channel and 2 channel. the 4 channel is for my speaker and 2 is for the subs. So I had hooked up the 4 channel amp and it sounded great! then all of a sudden i got a ton of ground noise introduced. WHAT HAPPENED? any ideas anything? this weekend I will be checking my resistance and verifying that is is below 1 necause i think it was something like 9

what you mean by that? that you have only one amp hooked up? or you had one hooked first and then when you hooked up the other then you got the ground noise? in many case when you hook more than one amps you are gonna have some ground noise.

What you can do is, you have to cut 2 thin wires same length and attach each one at the negative parts of your RCA wire connectors (the RCA wire of your 4 channel amp the one that power your speakers because there is were your hear the noise more compared with the subs), as shown in the pictures below and the other end of the thin wires  you have to screw them to your Head Unit metal case, make sure you connect them tight at your RCA wire connector or touch them up with solder it will help you eliminate the ground noise, it did happen with me, even ground loop isolators didn't help me like this. hope it will help you out.