Pioneer Avic D-3 issues

[UBERS4]

When my Avic D-3 HU is at low volume or off, there is a slight "hissing" noise that seems to emit from the speakers. We installed ground loop isolators to try to correct it and the noise still seems to be there, it's better (at least I think it is) but there. This problem started happening once the Avic-D3 headunit was installed and I never had the issue with the OEM headunit.

Also, the noise DOES seem to get louder when I accelerate. It is not however coming from the engine so it's nothing motor related.

Any help would be much appreciated. My installer is stumped as well. He told me not to worry about paying for anything until we fix the problem.

FYI, I have a 2005 Audi S4.

Thanks

[CX-7&A4]

Sounds like a grounding issue, OK it is a grounding issue.

[Matth13]

id say your not grounded.. the speakers should emit some noise if you are running a powerfull amp because the avc unit stays on forcing the amp to stay on whether its high or low volume its trying to giving juice somwhere( might be talking out of my ass but i had ground wiring kits on my a4 with 2 12's and stock oem headunit and had noise. cause of amps.. now i have the 07 a4 and the AVCd3 unit and it emits noise when volume is off but i think its the amp.. it goes away after i make it anywhere from 3-40 volume--

[Matth13]

the getting louder while accelerating sounds abit fisshy more like your not grounded though

[a2gtinut]

did you connect vehicle speed? which audio source?

[Grobby1]

You have a ground loop that is for sure. This is created by bad grounding. If the ground wire in the stock wire harness is used sometimes with after market head units this ground is not sufficient (ie. it goes to a common ground screw with a ton of other stuff). If you run a new ground for the radio it should help the situation. Also are you using the stock amp? Have you completely redone your system or just your head unit? A little more info on what exactly you have done would help.

[UBERS4]

I've only redone my HU, the amp and speakers are Bose OEM. I did not do the install, thus aren't sure on exactly how it was wired. I am going into my installer today and he's going to ground the RCA's. We've both come to the conclusion that it's a grounding issue. I'll keep you posted.