Help w/ Alternator Whine

[iMouseGTS]

I just installed a Pioneer DEH-P850MP HU w/ a Rockford Fosgate 160watt amp that powers the 12" RF sub. I am not using the stock amp, I cut the wires from under the glove box and extended those to connect to the HU. I spliced into the stock harness for 12V, ACC, and Ill. I didn't use the TA-03. Now I have some crazy alternator whine.

The power/ground wire for the amp is run along the driver's side, while the RCA for the amp is run along the passenger side. I grounded the HU to a bolt behind the passenger kick panel and grounded the amp to a bolt near the rear driver side speaker.

I've tried using a different set of monster cable RCA's and ran it straight thru the middle of the car over the seats, still had the whine. I even tried to twist the wires to make it twisted pair.

I have this old noise filter I got from radio shack and plugged it inbetween the 12V, still whines, then tried is for the ACC and Ill too, same thign.

Now here's a weird thing, if I hold the HU in my hand so it's not touching anything, unplug the ground wire and unplug the antenna, the HU is STILL ON. Isn't it supposed to turn off?

Any ideas?

[ScorpionX2]

Make your grounds as short as you can ( less than 3 feet if possible ) and scratch off any paint that might be under your ground points if you can. If that doesn't work hit me up with a pm and we will discuss it further

[ScorpionX2]

If you are bypassing the amp entirely, remove power from the amp too...that may avoid a ground loop

[iMouseGTS]

Hey, yea, I've tried unplugging the stock amp, the bigger harness right? Still got the whine. I haven't tried scratching paint off yet for a better ground, but I'll try that.

I'm still baffled that the HU stays on with no ground attached. Is that supposed to happen?

[mangoboy7]

I don't think the HU is supposed to stay on w/o a ground. That is kinda weird. I too get that whine. So shaving the paint of the ground will help? Will having the whine pose any problems?

[ScorpionX2]

The whine is usually from a ground loop....I have it in my car but its very very faint and only at high rpms so I haven't bothered messing with it...how bad are we talking here guys?

[iMouseGTS]

with the windows closed and the stereo volume at 1, it is bad. the loudest i can go with my stereo at the point it is going to hurt your ears is 40, at about 15-20, the whine can't be hurt anymore over the music.

[mangoboy7]

Mine isn't very loud either, but elimintaing it wouldn't be a bad idea. So i should try unplugging the stock amp?

[Defiler]

I've got the factory amp and head totally removed from my car, using balanced connections to the amps in the rear, and I STILL get some whine. I'm currently considering running a fresh wire straight from the battery to ground against, but that's going to be a real hassle.
I wonder if there's some filtering that could be used further up the line to remove noise from the factory ignition system. Anyone tried/seen anything along those lines?

[Brad Merrell]

1) Never cut wires.
2) A headunit can pull ground through its chassis, through you, through the antenna ground, or the ground wire.
3) You have a ground loop. Ground your amp to bare metal near the amp itself, scratch off the paint with sandpaper or the side of your crimpers. install a star washer under the ring terminal to dig into the metal. Cover the termination with primer or silicon to prevent corrosion or rust. Ground your radio to the factory ground wire or to the metal of the dash near the radio.
-or-
4) Your amp has been damaged, repaired or refurbished. A test bench typically has no provision to simulate RFI, so the tech has no way to know whether it will bleed through or not.

[tripnotic]

CAn y'all get whine when the HU is turn off?

Anyways, I don't have any whine in my car also I didn't scratch the paint off of the bolt on the rear sit. I use powerwire from Rockford and RCA from Rockford(dual wrapping/thread and it gray on the outside) also, which was recommended by the saleperson said, that it will eliminate the whine, which it did. Well, worth the money. Also, I run all of my wires through the center console throught the center box then to the rear sits.

What brand of RCA and powerwire are you using anyways?