Never ending Alt whine

[dalucifer 10+ year member]

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...

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[knukonceptz 10+ year member]

No need to test the ALT, the whine means it is working. Now to the problem:

You say no noise with RCA's unplugged. Is that unplugged at the HU or the amp. If at the amp, that eliminates the amp as the problem, unplug at the HU (plug back in at amp) That will eliminate the RCA's, only thing left is HU and the problem will be a ground loop.

Have you run 10 gauge wire from HU to the amp? Use 10 gauge speaker wire to power the HU of the same exact point the Amp gets power/grounds from (another reason to use power and ground blocks - eliminate loops) Do not attach the factory wiring for power/ground and see if the chassis mount is isolated from the rest of the car.

A ground loop is occuring, the voltage at the HU differes from at the amp. The RCA is the connecting path that has a lower ground resistance.

 

[Eldorado 5,000+ posts]

We tried 2 different h/u's

Same result.

But that was with the factory wiring.

We were going to wire the h/u directly to the battery but it was a late night and didnt get that far.

 

[knukonceptz 10+ year member]

Dont wire direct to the battery, the reason for the noise is a difference in voltage between components. So to correct that wire them together.

 

[forbidden 10+ year member]

Take the epicenter out of the picture and retest again. DO NOT test with the same model and brand of cd player as there may be a build issue with it.

 

[dalucifer 10+ year member]

epicenter isnt installed..didnt test the same model HU..I have the 9855 in and we tested it with an eclipse 8443

 

[forbidden 10+ year member]

Take the headunit to the amp and power it direct from the amps terminals. Jump the ignition to the constant on the deck harness. Use a new set of rca cables. Ensure that the amp is not mounted to any metal and that it is not touching any metal, put some cardboard under it. Do not plug the antenna in either. Retest and post the results.

 

[Eldorado 5,000+ posts]

We tried with the antenna in and with it out.

The whole car runs off 1 300A fuse going to a terminal

150A to the amp, 150A to the accessories

Ground is to the chassis, then goes to a grounding block, to the amp and to the accessories.

We know its not the amp or the h/u or the RCA's

Its either the stock wiring in the dash...or the alternator making noise and causing interfrence in the system.

The whole dash is plastic so there is no where else to ground to besides the floor of the car

 

[Eldorado 5,000+ posts]

Tried the seperate power/ground to the battery ( located in the trunk)....

Tried the RCA's removes from the h/u and plugged into the amp....

Still there....

 

[knukonceptz 10+ year member]

With RCA's unplugged at the HU and plugged in at the amp you have noise, what happens when you disconnect at amp. If you have no signal and noise, then unplug the RCA's at the amp and its gone, that would indicate its coming from the RCA's.

Use process of elimination to work down the chain of items.....

 

[Eldorado 5,000+ posts]

Tried that...no noise

But i ran another pair of isloated RCA's and it did the same thing

BTW...they are your RCA's ( Krystal Kables)

For top of the line they arent that great if they are making noise

 

[Flipx99 5,000+ posts]

knu -ygpm

 

[Civic_boi334 10+ year member]

This sounds like rigging but, its works. This what u do. If u r not u all of your amp jacks, get a piece of wire and wrap it around the one of the jacks on the back of the source unit and ground it to the source unit. It should stop it.

 

[dalucifer 10+ year member]

Actually...I only unplugged 1 of the RCA's and it got louder. i am assuming that it is a ground loop...Trial and error i guess..

 

[dalucifer 10+ year member]

This sounds like rigging but, its works. This what u do. If u r not u all of your amp jacks, get a piece of wire and wrap it around the one of the jacks on the back of the source unit and ground it to the source unit. It should stop it.

Tried it..