Ok guys i have a 2006 charger. It supposedly has a 180 amp alt in it. Over the past few weeks i have done everything i could possible think of to get rid of this alt whine. Change grounds on the HU and the AMP.Changed RCA's. Ran an isolated ground to HU from the battery. Gave the HU an isolated power to an external battery. Seperate ground to the alt with the stock wiring in. New alt power wire with the stock wiring as well. Took the serpantine belt off the pully's to see if there was any catching in the alt(no catching nor was there an play in the alt shaft). Went and got the alt tested today its a good alt. Got the battery tested and its a good battery. The only time that there is no alt whine is when the RCA's are unplugged. The other time that there was no whine was when the HU power/ ground was isolated aswell as the amp being isolated.

I am pretty lost now on what it could be...Any help is appreciated...

try a diff hu my guess would be the outputs of the hu

tried that aswell....forgot to add that in..

bench tested the amp and it worked also..

Edited July 7, 200619 yr by dalucifer

Were both the HU's Pioneers? If so try grounding the outside shell of the RCA's and see if that helps the noise. Just do it temporarily with some clips. It is a known problem with some Pioneer/amp combinations.

http://www.mp3car.com/vbulletin/showthread.php?t=46031

that is def a good read..

Were both the HU's Pioneers?  If so try grounding the outside shell of the RCA's and see if that helps the noise.  Just do it temporarily with some clips.  It is a known problem with some Pioneer/amp combinations.

<{POST_SNAPBACK}>

Alpine 9855 and eclipse 8443

ok, time to use some logic - rather than just shooting in the dark.

First you need to make a set of shorting plugs. Go to radio shack and get an el cheapo set of RCA plugs (male ends) that can be wired up. Take a small peice of wire and connect the two terminals inside the plug together, have it soldered if you can - you are doin a pair of these. Unplug the RCA's from the amp and pug these in, in their place. Turn on the stereo and see if the whine is there. Let us know what happens.

j/w, what will this do ?

it will tell you if the amp is noisy ..... if it is, we can troubleshoot that, if not - we can move to the next item up the chain. The shorting plugs just make sure there is no noise inductance because of the no load on the inputs

Would taking a pair of RCA's and shorting one end out while the other is plugged in do the same thing ?

yea, if I understand what you wanna do