Ground questions.... Any negative effects with ground loop isolator ?

[sdmtnbiker420 10+ year member]

Hey guys, I had alternator whine with my newly installed 4 channel amp and Pioneer 6900-UB (both installed at the same time).

The amps are grounded under the back seat, while the Pioneer deck is using the negative in the OEM harness (1999 Pathfinder), which leads me to my first question - Should I eliminate the OEM ground? Is it OK to disconnect the OEM ground, and ground the Pioneer to the metal bracketry in the dash? Could this possibly help solve my ground loop problem?

The problem was eliminated by installing an inline PAC "ground loop isolator" on the RCA's of my rear co-axials. There is absolutely no more alternator whine. What are the effects on sound quality with this device? Is this a "filter" or does it just eliminate the ground at that point?

I have not even tried installing on the front component RCA's - I was much too happy after discovering the PAC ground loop isolator worked, (at least temporarily) that I did not want to mess with it anymore. I do not know what the effects would be, but i'm guessing it would be the same. I would rather have this "filter" on my rear fill rather than my front soundstage.

Your opinions and insight are greatly appreciated, thanks in advance.

-SD

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[azimuth 5,000+ posts]

the isolator works fine. yes, you can ground the head unit separately from the oem, which is what i did. i didn't notice any difference in sq between the 2, but i did get rid of the isolator. more of a neatness issue than anything.

 

[spoonraker 10+ year member]

A ground loop isolator is a tool used to help you determine where your ground loop is, they are not a permanent fix.

Since hooking up the isolator to the RCA coming off your head unit to your amp made the noise stop, that means your head unit is the source of your noise.

Since your head unit is a pioneer it is likely that you need to ground your RCAs to the chassis. Also using a different ground then the factor one from the harness won't hurt either, even using your own power wire might not be a bad idea if the noise still won't go away.

 

[luvinthebass 5,000+ posts]

i used to use a ground loop isolator cuz my pioneer had that dreadful alternator/engine whine and fixed it by readin that thread on here that telled you how, when i had the ground loop isolator, it was bout a year ago or so you woulnd't get alot of bass with it connected, but the highs were VERY clear with clarity, i took it out and had way more bass and the highs from my fronts were noticably better kinda, so you win some and you lose some when it comes to car audio

 

[sdmtnbiker420 10+ year member]

Nearly 1 week after installing the ground loop isolator, which worked, the noise mysteriously made it's way back into my car.

I did not change a thing!!! How could this have happened???

I hate extra noise!!!!!!!

 

[jmoreno150 10+ year member]

ground the rca jack on the h/u just wrap wire around each jack to ground.