Originally Posted by Thebestestdrummer
how do you ground the case? how to you ground RCAs? I might also be looking into a newer aftermarket stereo with 3 sets or pre outs, mine only has 2. Could that also possibly help?
and the power and the RCAs are ran on the opposite side.
take a short length of bare electrical lead (not single strand wire) and wrap it around the outside of each RCA post and collect them at any exterior casing screw, this grounds the negative side of the RCAs to the case if you have an internal RCA ground fuse gone. Then take the a lead and from another exterior case screw and run it to a clean body ground, this will ground the case to the frame, and should alleviate any RCA signal distortion.
Multiple RCAs won't cause any issues, they are just signal outs, but if you do get a new head unit, that would be a simple way to tell if you have RF interference or RCA noise.