I have a '79 vette with a factory AM/FM/CB radio installed. When the radio is shut off, I can hear a buzzing or whining noise coming from the speakers. The guy who had the car before me installed a rocker switch in the fuse panel to shut off power to the radio when it's not in use because of this. Not a good solution.   I've seen noise filters advertised that go in between the alternator & the battery that claim to "eliminate alternator noise". Don't know if they work...

Has anyone else has had this problem & found a solution for it?

The filters I have used in the past were from Radio Shack..it went in line with the power and ground of the radio..easy to put in and they work pretty good..

Rich

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My first parade at Carlisle 2010

Tke the Bee's out of your speakers!!  That will solve the problem!!  lol

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Dan is always such a big help.

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These are some good suggestions (less the bees).

If trhat noise accelerates and de-accelerates with the speed of the engine then it must be generator interference, or alternator.  If you have an AIR it could be that also.

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I agree with checking the ground connections.  That could well be the problem, especially if the problem exists with the radio turned off.

The buzzing yo hear is called ground loop.  It is caused by static electricity feeding back through the grounding in your speakers themselves.  And it in turn feeds a positive charge back to the Radio.  I would suggest that you first check the ground at the radio.  Literally loosening and then tightening the ground again.  Then I would check the grounding at each place from the body (birdcage) to the frame, including the Battery ground to the frame.  Loosen and then retighten.  There is about 6 locations.  Pretty easy to get to.  Installing the filter will not hurt either way.  They are not expensive, and easy to install.  And will usually improve your sound system as well.  They are called ground loop isolators.  Would not hurt to go ahead and install one while you have the radio out to tighten the ground anyway.  I would not be shocked to find that the buzz is coming back to the radio from the Amp meter in the gauge cluster.  And would check each ground connection while you have a chance on the back of the gauge cluster.  Time consuming, and kind of a pain in the butt, but the grounding wire loops from one gauge to the next. It could also come from one of the relays for the headlights, wiper door, horn, and even the ignition coil not having a good ground.  If it gets worse when you accelerate, then it is ignition related I feel. Grounding is everything being that the only steel  is the frame and the birdcage.  As i said, real time consuming.  A simple trouble shoot technique is to make a 15ft long jumper, connecting one end to the Negative post on the battery, and an alligator clip on the other end, then you can move it from one spot/ or device to another, giving you a direct ground.  12awg atleast. 

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Hi JIM,  Noise in car audio is fairly common, but to have noise in speakers with the radio powered OFF is unusual. It is helpful to first identify the cause of the noise before changing wiring or adding filters. You can use a portable radio to sniff out the source of the noise by tuning it off-station, and moving the radio around under the dash and under the hood. If you hear a similar buzzing in the radio, then you need to check out that nearby component.

 

The old GM service manuals classify the 3 causes of audio noise as:

 

1.       FRONTWAY: Coming in thru the source being played, such as being picked up by the antenna when playing the AM/FM.

 

2.       SIDEWAY: Being picked up by the circuit in the receiver thru the air, generated by a nearby component such as the distributor.

 

3.       BACKWAY: Coming in directly thru the wiring of the receiver.

 

The cure for #1 is to reground the radio and/or add a filter on the antenna cable. The cure for #2 is to shield the component and/or the radio chassis. The cure for #3 is to add a filter on the power wires to the radio and/or install a filter on the component generating the noise.

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Joe T