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could an amp cause alternator whine?

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=111983
Printed Date: May 17, 2024 at 6:30 PM


Topic: could an amp cause alternator whine?

Posted By: lazybum
Subject: could an amp cause alternator whine?
Date Posted: February 27, 2009 at 10:49 PM

I have been having alternator whine problems for the longest time. I have no ground loops, my head unit is still in working order, so i was thinking this may be the amp? Is this possible? (RCA's and power cable's were run on opposite sides of the car, no ground loop)



Replies:

Posted By: i am an idiot
Date Posted: February 27, 2009 at 10:59 PM

An amp can cause engine noise, however it is more likely that you have a Pioneer radio and it has a problem.  The amp being the problem is rare, some older Kicker amplifiers have the same fuse as the pioneer radios have.  They do blow on occasion. 

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





Posted By: haemphyst
Date Posted: February 28, 2009 at 1:22 AM
Unplug your RCA cables at the amplifier. Does the noise stop? If so, plug them back in, and on the other end, (however you have to do this) connect the pin to the shield with a 10K resistor, and the shield to the chassis. (This simulates the output stage of the deck.) Does the noise return? If so, then you HAVE A GROUND LOOP.

BTW, running the RCAs next to the power cable cannot cause noise, and even IF the current in your car WAS AC, and you were to have noise, then that is NOT ground loop, that is induced noise.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: lazybum
Date Posted: March 01, 2009 at 12:47 AM
I don't think it's a ground loop, because i've gone over all my grounds, the only 2 audio grounds that would be in the car are my radio and subs, because it's the only thing not factory.  And i even ran a wire from the radio ground to the same place my amp is grounded.  (not using the factory radio ground)  I had my head unit tested, and my head unit is fine, and my amp is kind of a crappy amp.  It's a power acoustik OV2-220.  Also, stupid as it sounds, my RCA's are in the RC out pre-out on the amp, because somehow, my RCA In's snapped off...  (I know it's stupid, but it still made the subs hit)




Posted By: lazybum
Date Posted: March 01, 2009 at 12:52 AM
And sorry for the double post, but i forgot to mention, the whine is strictly coming from the subs, not the speakers.




Posted By: haemphyst
Date Posted: March 01, 2009 at 1:44 AM
haemphyst wrote:

Unplug your RCA cables at the amplifier. Does the noise stop? If so, plug them back in, and on the other end, (however you have to do this) connect the pin to the shield with a 10K resistor, and the shield to the chassis. (This simulates the output stage of the deck.) Does the noise return? If so, then you HAVE A GROUND LOOP.

You could have ONE ground, and if you haven't done anything to SPECIFICALLY rule out groundloops, then you can still have one. Follow those steps above: report back.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: i am an idiot
Date Posted: March 01, 2009 at 8:55 AM

Since the input RCA jacks got ripped off the front of the amp.  When that happened there is a good chance that the ground path of the output RCA jack of the amp. 

Remove the front cover from the amp.   (4) 2.5 MM allen screws that attach it to the heat sink.  Then there will be at least 1 in each of the RCA jacks.   After removing that cover, gently press the RCA jack toward the center of the amp.  If it moves easily, there is probably a broken connection on the bottom of the RCA jack.  You can either remove it and repair the broken leg or if you do not feel like taking it apart, you can solder a wire to the RCA cable as in the instructions I posted earlier.  You did read them, didn't you?  After soldering the wire to the RCA cable, attach the other end of the wire to one of the non bridged speaker terminals of the amp.  It is very critical that you use one of the terminals that is not needed when bridging the amp.  A bridged wire would cause damage.





Posted By: lazybum
Date Posted: March 01, 2009 at 12:04 PM
haemphyst wrote:

haemphyst wrote:

Unplug your RCA cables at the amplifier. Does the noise stop? If so, plug them back in, and on the other end, (however you have to do this) connect the pin to the shield with a 10K resistor, and the shield to the chassis. (This simulates the output stage of the deck.) Does the noise return? If so, then you HAVE A GROUND LOOP.

You could have ONE ground, and if you haven't done anything to SPECIFICALLY rule out groundloops, then you can still have one. Follow those steps above: report back.


Should i do this to the red RCA or the white RCA?




Posted By: haemphyst
Date Posted: March 01, 2009 at 1:11 PM
Both first, then one at a time. Whatever. Wherever the noise IS, that is where you offense is. If it turns out that you only have one burned RCA ground trace somewhere, then the noise will only appear on one channel, with one RCA plugged in. It really won't matter - the repair will be the same.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."





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