Sorry for the super Necro. With that out of the way.Sometimes alternator whine is super hard to correct with cheap RCA’s. Where/how are you grounding the amp?
Matter of fact the HU is grounded as well to the old head unit ground. When we bought the car it had a Pioneer AVIC unit from 07, but the sub and amp had been removed before we purchased it. So the HU is grounded behind dash, and amp is grounded at battery.It’s anyone’s guess as to the RCAs. If any portion is in shielded it can allow in noise. Un-mount the amp and insulate the chassis from ground. Check the noise. Then run a direct ground to the battery and see if the noise changes.
Is this the only item you have at this ground point?
I troubleshot a ground loop issue years ago that ended up being a set of cheap 90 degree fittings at the back of the deck. We installed the head unit, and then the amp separately. To save money the guy we were installing for pulled the deck and ran
a set of Stinger RCA. Took 2 days to track down the cheap conectore
I want to say it 1, but no they do not run with the RCAs the battery is in the trunk and the amp is also in the trunk.What gauge power and ground wires? Do they run with the RCAs at all before the amp?
She likes the way its set now so I won't fiddle too much with it. I am going to do mine next and will see what happens.I’d say the problem is internal to the amps filter circuits. Any noise getting induced by the cables should get worse with no filter (full pass).