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wierd noises.

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=110756
Printed Date: May 10, 2025 at 5:38 AM


Topic: wierd noises.

Posted By: big samson
Subject: wierd noises.
Date Posted: January 17, 2009 at 7:58 PM

so my buddy and i installed a deck, components, 2 ways, subs, and 2 amps in my 94 325is. cakework. everything is properly grounded (that we can tell) all the equipment is in good working order, and we have 30 years install experience between us. All the stuff was in my 94 318 a couple of months ago. Long story short, there is 60 cycly hum WHEN THE CAR IS OFF and horrible alternator whine when its on. The 60 cycle seems to modulate some as well. i am stumped. the hu is grounded directly to the factory hu ground, and amps to the battery (was originally the chassis, but this actually took some of the noise out)  any ideas?

pioneer 5900bt

polk momo components

polk db 2 ways

polk momo 12s

fosgate 450.4

infinity 1600 a




Replies:

Posted By: i am an idiot
Date Posted: January 17, 2009 at 8:23 PM

Triple your money back guarantee offered if this does not fix your problem. 

https://bcae1.com/images/rca/temporaryrcashieldrepair.html

When you were installing your equipment, you failed to disconnect the battery.  Either a power wire touched the shield of your RCA cable, or you connected power and RCA cable before you connected the ground wire to the amp.  When power is connected to the amp, it begins looking for ground.  It found it via your RCA cables.






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