Alternator whine

[amagalla]

OK. I need some help here. I've narrowed down the source of the alternator whine to the head unit (HU). The way I did that was I replaced the HU with another (an Alpine unit I have here) and the noise went away. I used all the same electrical connections. So, it look like my HU is sensitive to noise. I tried grounding the RCA plugs. It only added more noise. My question is: How do I eliminate the noise in the HU? I've tried a better ground, noise filters (of questionable quality) on both constant and switched power. Any other advice?

Thanks.

Tony

[dghii]

Man, I feel for you. I have an electrical engineering degree and sometimes find these problems to be near impossible to solve.

I replaced my CDR-220 last year with a JVC Bluetooth unit. I used a Metra harness adapter for the HU. I had all sorts of noise! I tried ground loop isolators, noise filters, ran dedicated power and ground and had absolutely no luck. Conneting the CDR220 back up and all was quiet!

I finally ran my speakers directly to the HU and the radio works with no noise at all.
Screw it.

[Run]

I have the exact same issue. Ran both HU and amp to direct ground on battery no help. I also tried noise filters whine just as bad. Its annoying the hell outa me

[78F350]

I am not a big stereo guy and have forgotten most of my electronics education, but I have to wonder if the root of the problem is the alternator rather than the audio equipment. Too much AC output? Weak internal grounding?

...just wondering in public, not pretending to have a clue.

[dghii]

Originally Posted by 78F350

I am not a big stereo guy and have forgotten most of my electronics education, but I have to wonder if the root of the problem is the alternator rather than the audio equipment. Too much AC output? Weak internal grounding?

...just wondering in public, not pretending to have a clue.

Could be. In my case, I had replaced my alternator's voltage regulator less than a year ago so I'd guess that wasn't my case.

It is frustrating!

[amagalla]

I'm gonna sat "No" since the other HU seems to work with no prob.

Tony

[amagalla]

OK. I'm about to go nuts here. I've tried power line filters, new (better) ground, grounding the RCA plugs, and now RCA ground loop isolaters and all with zero effect. The next (and last I think) thing I'm going to do is to try a direct power/ground run from the battery. If that does not work (which I kind of doubt), then I'm at a total loss. I'll just have to learn to live with it.

Tony