I installed a head unit around may of last year and things were going great until today. I started the car up and I hear a high pitched sound coming from my speakers when the stereo is on. If I turn off the stereo off, the sound goes away. It's very annoying because now I have to turn up the music louder to drown out the sound. The higher the revs, the higher in pitch the sound gets. Its very annoying around town and less annoying on the freeway.

I checked my stereo's ground and it looks good. I cant figure out why it would do that all of a sudden after 5-6 months of use. My car originally came with the Bose system that I replaced with a Clarion head unit using the Schosche adapter. It seems that the high pitched sound is mostly coming from the center channel speaker but I could be wrong.

Thanks

 

it could be you need new plug wires of that another wire that caries power has fallen near it.

 

Speaker wire is crossing or is near a wire with power running through it. Check the speaker wire routes.

 

Perhaps a conductor drifted in the proximity of your fuel pump. Gotta stay AWAY from the fuel pump.

To test: Run Audio with car off (accessary position). No squeal ? Could be fuel pump.

Good luck. May your squeal stop squealing. Post your results

 

almost all the time its either this or a poor radio / amp ground

 

I'll check the plug wires, thanks. As for my stereo, I only have the headunit powering the stock Bose speakers and factory amps. None of the speaker wires were touched. The high pitched sound is only present when the engine is running and has all the symptoms of a bad ground. I'll check my ground once again and maybe move it to a different place. I just think its weird that this problem occured half a year later instead of right away. I really appreciate the help. If you have more ideas, keep them coming. All the threads I've read about this point to a bad ground but in all of these, the problems starts the minute they start the car with their recently installed stereo.

 

You most likely have a ground loop. Somehow something in the audio system has developed a ground problem and is picking up electrical noise from the ignition and alternator.

If the noise is coming from only the center channel then the ground of the center channel is the most likely problem. If the noise is loudest at the center and fainter in the rest it is still probably the center channel since the Bose amps share a common ground harness. The noise could come in through the center and spreading to the others. Try unplugging the center channel amp and if the whine goes away completely you just found the problem.

If the sound is coming from all the speakers equally loud then it is the head unit. Try running a new ground for the head unit without going through your Schosche adapter. Go directly from the head unit to the chassis and see what happens.

 

Make sure your battery is grounded well.

 

I havent had time to mess with it more since the weather sux right now but I think the sound is equally as loud on all front speakers. I'm running a ground directly from the headunit to the chassis. If it stops raining for a bit, I'll move the ground to a different spot and see what happens. While I was looking at the headunit, I noticed that one or two of the RCA inputs lost its little rubber cap, exposing the female connectors. Could these be picking up the engine noise?

 

I have an added wire grounding the battery to the chassis.

 

It certainly could if that connector was touching the metal chassis! If you have unused RCA inputs it's best to short them to ensure they cannot pick up noise. This does no damage to the stereo as long as it is an INPUT you are shorting. Go to Radio Shack and find the cheapest plastic RCA plugs you can. Short the center pin to the outer collar by soldering or crimping them together and just slip them onto your unused inputs. You can also take some cheap, free RCA cables that came with something and strip the jacket. Then just twist the center conductor and the braid together and wrap some tape around it. Presto! No way noise can now enter through the inputs.

I built my own cables to run to my amp and used RCA plugs with metal barrels. I had to make plastic sleeves to slip over their outsides to ensure the barrel couldn't touch the metal dash and pick up a low level whine.

 

How hard is it to reach the plug for the center speaker amp? Can I remove that cover on the passenger side of the tranny tunnel to access the amp? Sorry for all the questions. Normally I go outside to figure it out but its been raining pretty hard these past days and since Im tall, its dificult to work inside the car with the door closed.

Thank you everyone for the help I've gotten so far.

 

You're getting hammered by rain to, eh? The last couple of weeks haven't been very FD friendly.

Since this changed by itself recently and you're not sure if it's the center speaker or not...

If you're using RCA outputs (e.g. connecting the head-unit to an amp or scoshe adapter??), be sure the associated RCA cables have a ground connection that is intact. Maybe rotate the male barrels around the female connectors to 'rub off' any oxidatation that may have appeared due to the recent influx of moisture.

Also, there's a 'condenser' capacitor mounted right next to the igniter module meant to help reduce its EMI (and provide a local charge reserve for the ignihter). That might be worth a quick check... but I'd look at other causes before spending more than 2 minutes on this idea.

 

Im not using any aftermarket amps. Just the Clarion headunit and the stock speakers. The scosche adapter gets wired up like a standard car specific stereo harness. It doesnt use RCAs. I brought up the RCAs because my headunit has a million RCA, inputs dangling back there, that I will never use. I'll look into that condenser capacitor.

It stopped raining for a minute over here. By the time I went outside with my keys and some tools, it started pouring again. It's supposed to stop raining on wednesday. Hopefully I can get some work done on the car.

Thanks

 

do you have the stock amps still in place? because if you do are supposed to bypass them and go from the head unit to the speakers.

 

I still have the stock amps in place. As far as I know, if you have a Bose system, you're supposed to use the Scosche adapter to give the amps the correct power levels and get sound from your speakers. My sound system is stock except for my Clarion headunit. If I had aftermarket speakers, I can see how bypassing the amps is a good thing (like FCs).

 

DamonB,

You were right about the center speaker amp. I put my ear at the door speakers and couldnt hear the whine. The whine was only coming from the center channel speaker. After I unplugged the amp, the whine went away. Thanks for the heads up.

Now that the culprit was found, how do I fix it? Can I simply add a ground wire to it? The FSM doesnt go into details on any of the amps (atleast I dont think it does). I'd love to get the center channel speaker working because theres a huge difference in sound without that speaker connected.

Thanks!

 

Fixing it is a whole different ball of wax! My intentions were to isolate the problem first. Since everything was fine and then one day it started making noise then most likely there is some sort of component failure in the amp itself. All I would do is closely inspect the wiring and connector at the amp. You might also try adding a wire from the amp's metal chassis to the car chassis to be certain the amp is properly grounded. If you then still have whine I would replace the amp. I bet you could get one really cheap as many don't use them anyway.

 

After reading what I wrote above, I apologize if I sounded like YOU had to fix my problem. It wasnt my intention.

I'll remove the console tomorrow and try adding a ground to the amp's body. Hopefully that will work. Can I "beef" up the stock amp ground by adding another ground wire to the amp's B/O wire? If I'm not reading the diagram wrong, that wire is a ground?

I wasnt sure how to remove the center console last night so I couldnt actually see the amp. I stuck my fingers under the console and just unplugged the amp. It took me forever to find that amp! haha. The FSM shows the amp by the glove box. Good thing my flashlight died or else I would have removed all kinds of interior pieces looking for it. Lucky for me, I remembered someone saying it was under the center console where your elbow would sit. By the time I got to the amp, it was pretty late and pretty cold. I know us californians are sissys when it comes to the cold.

 

If the amp has a component failure inside it then adding a ground won't help, it's just something simple you can try to see if you get lucky. Don't bother splicing into the harness, just run a wire from a screw on the amp's metal case to the chassis of the car. If this doesn't fix the problem I would try replacing the amp.

 

I finally had time to mess with the car. The amps casing is plastic. I doubt grounding it will do me any good. I tried it anyways but the sound was still there. Im debating on buying another amp or gettin an aftermarket center speaker and feeding it power from both front speakers. I'm worried that the aftermarket speaker will be very loud, making the sound system sound crappy. Should I be worried?

 

You can't simply feed the center speaker the same current from the left and right speakers. The left and right has to be summed and then fed to the center and that's one of the things the center channel amp does. I'd do one of two things, either replace the center channel amp or remove the center channel speaker.

 

Hey i have the same issue.. how did you get it fixed??