Alternator Whine After Semi-Rewire

[e3088ix]

Just installed a Kenwood KDC-HD458U in my 1988 325ix (premium sound originally). After reading tons of info (especially stereoinstaller1, if you read this thanks!) I bypassed the amp in a way he theorized as a new way where I made the connections under the rear seats. I then brought the rear speaker negatives up through the front speaker negatives, using some wire I cut out of the original wire to make new lines from the front speakers to the head unit for the front wires. Took a long afternoon (first time) but all is done and it looks great! Sounds great too!
Until I turned the engine on. Relatively loud alternator whine. I can hear it with the windows down and the music pretty loud or any combination of any variables.
I read in other threads (from stereoinstaller1 again) that the amp bypass should rid it of whine but no luck. And also the alternator is about 10k miles old, so its not going out.
Thoughts? Suggestions?
P.S. its on any content being played and this is a brand new HU

[jlevie]

The whine has more to do with the new head unit than the rewiring. Make sure it is properly grounded. You may have to use an RFI filter on the HU's power input.

[e3088ix]

That's what I was leaning towards. I did use the original ground from the old head unit wiring but the whole is more noticable now I feel. I'll try a filter out and see how it goes

[StereoInstaller1]

no no no...this isn't 1977, we don't need noise bombs, there is something seriously wrong. New decks and amps just don't have noise issues, I haven't used a noise bomb since the early 90's, not one.

You need to test to make sure you have zero chance of chassis ground on any of your speaker wires. I guarantee there is a wiring issue-and one that will piss you off.

Pull that deck and meter between chassis ground and each of the 8 speaker wires, something is grounded somewhere. I am not sure where the issue is, but I bet you find it.

Luke

[jlevie]

I agree that a modern HU should not have this problem, but I have seen some that will whine in an E30 or other older vehicle that are dead quiet in a more modern car.