alt 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=116784
Printed Date: May 01, 2024 at 8:19 PM
Topic: alt whine
Posted By: djrankin004
Subject: alt whine
Date Posted: October 07, 2009 at 1:57 PM
Have a front set of components hooked up to a two channel amp. Getting loud alternator whine through them. When i disconnect the rca's the whine stops. What could be the problem, or how can i narrow it down.
Replies:
Posted By: djrankin004
Date Posted: October 07, 2009 at 2:00 PM
Also i tried a ground look isolator but the speakers sounded awful when it was hooked up. They seemed to echo and cut in and out. Not sure if that is relevant. All equipment was professionally installed so i'm assuming to power wire and rca's are on opposite sides of each other
Posted By: haemphyst
Date Posted: October 07, 2009 at 2:37 PM
djrankin004 wrote:
Also i tried a ground look isolator but the speakers sounded awful when it was hooked up. They seemed to echo and cut in and out. Not sure if that is relevant.
Probably a cheap GLI. Also ANY installation of a GLI is a bandaid, so let's see if we can get you taken care of without it. Pioneer radio? I bet you this is the fix... And if it IS the fix, then your system was NOT very "professionally installed"...
djrankin004 wrote:
All equipment was professionally installed so i'm assuming to power wire and rca's are on opposite sides of each other
If the noise went away with the installation of the GLI, then you should have already been able to figure out that was not the issue. It does not matter anyway, I've run every wire (signal, remote, power and speaker) down one side of the car in MANY installations, (the current one included, with the exception of the speaker wires...) and I've never seen it cause alternator noise. ------------- 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: djrankin004
Date Posted: October 07, 2009 at 2:53 PM
It is an alpine radio. I've been told it is most likely the amp. The volume of the whine goes up and down with the gain of the amplifier and the rpm's of the car. Power Acoustik 2 Channel amp btw
Posted By: haemphyst
Date Posted: October 07, 2009 at 2:56 PM
Try the fix suggested, anyway.
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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: d_rock_81
Date Posted: October 07, 2009 at 3:01 PM
make sure your head unit is grounded separate. Don't use the factories radio ground. be sure to have the amp on a rack so its not grounding out through the body of it. Use a top quality rca cable.
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Dustin Rockney
Rockstar Autosports
Posted By: djrankin004
Date Posted: October 07, 2009 at 4:21 PM
could my common ground from this amp and a subwoofer amp through a distribution block be a problem also?
Posted By: i am an idiot
Date Posted: October 07, 2009 at 4:52 PM
Disconnect the RCA cable and the speaker wires from the amp. Using an ohm meter, check the resistance between the shield of the RCA jack of the amp to one of the non bridged speaker terminals of the amp. Let me know what you come up with.
Posted By: djrankin004
Date Posted: October 14, 2009 at 4:22 PM
sorry about the delay. using a multi meter i could not get it to come up with any resistance between either rca shields and the speaker terminals of the amp. I tried multiple combinations with the car on and off(you didnt specify so i wasnt sure if it mattered). Is the multi meter i used broken? It read resistance from my speaker wires and my subwoofer terminals
Posted By: i am an idiot
Date Posted: October 15, 2009 at 9:04 AM
Touch the meter leads together to see if your meter is broken.
Do you know which of the speaker wires are NOT used to bridge the amp?
If so, remove all fuses from the amp. Place a single 5 amp fuse in one of the fuse holders. With the RCA cable and speaker wires disconnected, make sure the amp powers up. If it does, connect the speakers and RCA cables. Turn the volume all the way down on your radio. Connect one end of a small wire with one of the non bridgeed speaker wires. With the amp turned on, and engine running. Briefly touch the other end of that wire to the shield of the RCA jack This should make a pop, that might blow the fuse, or if the fuse survives the pop, the noise should go away. If the 5 amp fuse does not survive, place a single 10 amp fuse in the same spot the 5 was in. Let me know what you find out.
Posted By: djrankin004
Date Posted: October 15, 2009 at 9:43 AM
I borrowed the meter so dont have a clue if its broken. What should it do when i touch the leads and what setting should i have it too(AC, DC, OHM?) I'll give it a try, but it might take me another couple days or so, big weekend ahead. Thanks
Posted By: djrankin004
Date Posted: October 15, 2009 at 5:39 PM
Just to verify i am touching the small wire from one unbridged speaker terminal on the amp to the shield of one of the RCA wires? or am i touching it too the shield of the rca input on the amp?
Posted By: i am an idiot
Date Posted: October 15, 2009 at 8:08 PM
The RCA cables should be plugged into the amp to do this. You will have to touch the wire to the outer part of the cable. Motor running and noise coming through the system. Then touch the wire to see if the noise goes away. your meter should have been set to the Ohms selection.
Posted By: boxhead78
Date Posted: October 16, 2009 at 2:11 AM
get your rca wires from by your power wireand run them on the other side of the car it should stop
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boxead78
Posted By: djrankin004
Date Posted: October 20, 2009 at 3:17 PM
okay sorry about the delay. I disconnected the speakers and rca wires. Replaced the two 30 amp fuses with a single 5 amp fuse, powered on the amp, and the fuse did not blow. So i reconnected the rca's and the speaker wires as you told me. And placed a small piece of wire into one of the non bridged speaker terminals. I turned on the car, turned volume all the way down, with whine coming out of speakers. I touched the small wire to the rca shield as instructed but nothing happened. No pop, no sound at all actually. And the whine still persists. The model on the amp appears to be the Power Akoustic FI2X-520 although i cant find any info on this amp. Its a two channel 500 watt. What now?
Posted By: DYohn
Date Posted: October 20, 2009 at 3:32 PM
My guess is bad ground or defective amp. HERE's how to check your ground... ------------- Support the12volt.com
Posted By: djrankin004
Date Posted: October 20, 2009 at 4:05 PM
The amp has been used prior to this for subs. It is wired up with a 2 ohm load to each channel and i am using the crossovers that came with the components. I'll double check the amp ground though with the test you provided. Any chance of fixing this defective amp if that be the case?
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