Alternator Whine

Printed From: the12volt.com
Forum Name: General Discussion
Forum Discription: General Mobile Electronics Questions and Answers
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=1091
Printed Date: July 15, 2025 at 10:12 AM

Topic: Alternator Whine

Posted By: GMC4x4Guy
Subject: Alternator Whine
Date Posted: June 03, 2002 at 2:07 AM

I just finished installing a high-end competition sound system in my car. I've installed several sound systems before but never had a noise problem, until now. I have a case of the dreaded alternator whine. I grounded every component, including the deck, to one location, so I figured that ground loops are not my problem. I'm using scoche RCA cables and they never touch any power wires. I have a few RCA cables running a foot away from my power/ground distribution center, but I don't think that's close enough to be my problem. I guess I don't have enough experience with this problem because I am at the end of my road. Please help!

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"Drive it like you stole it"

Replies:

Posted By: Big Dog
Date Posted: June 03, 2002 at 2:21 PM

Hey GMC4x4Guy,

Am I to assume it's in a GM? You might have one or more diodes broken down in the alternator take it to a shop for tests. There are also several tests you can do first. Unplug the RCA's from amp then short the center pin and shield of every input to amp. Is it better? Then amp and its wiring is O.K. The noise could be RF induced meaning a component such as head unit or EQ is picking it up "through the air" try moving the component away from dash if it reduces then shielding might be necessary. If it doesn't change then it's coming down the line somewhere. Unplug the antenna. Is it better? If so then cut the shield or replace it. Unplug your EQ and plug amp directly to radio. Is it better? Probably the EQ's at fault - poor isolation or cracked PC board. You can also try removing the shield at the connector before it enters amp, at times certain RCA's which have the shield isolated from the connector take care of this problem. Hope this helps!

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Prepare your future. It wasn't the lack of stones that killed the stone age.

Posted By: NyxBass
Date Posted: June 04, 2002 at 3:31 PM

Try this for starters:

https://www.the12volt.com/installbay/display_topic_threads.asp?ForumID=2&TopicID=874&SearchPagePosition=1&search=noise&searchMode=allwords&searchIn=Topic&forum=0&searchSort=dateDESC&ReturnPage=Search

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/NyxBass

Posted By: Big Dog
Date Posted: June 07, 2002 at 11:48 AM

Hey NyxBass,

Why did you tell him "Try this for starters:" when he has alternator problems? posted_image

Just kidding! posted_image Hey it's Friday!

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Prepare your future. It wasn't the lack of stones that killed the stone age.

Posted By: Velocity Motors
Date Posted: June 07, 2002 at 12:45 PM

Good one Big Dog !! posted_image I like that.....

Are you the same Big Dog as in Metra moderator forum ? Just curious ??

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Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA

Posted By: Big Dog
Date Posted: June 07, 2002 at 2:52 PM

Hey Jeff,

No, that Big Dog's been neutered! posted_image

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Prepare your future. It wasn't the lack of stones that killed the stone age.