Electronic Noise

Hey guys... what could cause a constant, and annoying electronic buzz in my 1993 5.0. The previous owner installed an aftermarket stereo, tach, etc, but I really don't think that is it.

The noise is constant when the car is on. Doesn't go away no matter what you do inside the car, not does it ever change.

So I'm thinking something under the hood. But I don't have a clue where to look or what to do. I guess I can replace the wires, plugs, cap, etc, but something tells me that ain't it. It's too constant to be related to speed/revolutions.

Anyone, anywhere, have this problem before?

Thank you.

Brad

Reply to
Brad and Karen
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"Brad and Karen" wrote in news:Olzlk.112852$kx.106779@pd7urf3no:

Maybe the fuel pump?

Reply to
Joe

Try pulling fuses one by one to isolate the source of the noise. Alternator , ignition noise usually varies with RPM though. Ignition noise ''pops'' and alternator makes a whine. Noise in radio or in tape/cd mode? Radio noise usually comes in via the antenna. Good grounds to radio? Chassis ground to radio frame is important for it's shielding. Check all the grounds especially the battery to frame and body. Power to radio shouldn't be shared with a noisy circuit like the tach., fuel pump, heater, etc. . Motor make electronic noise as well as the ECM Most aftermarket radios I've had turn to crap after a the miles go on.

1993 5.0. The previous owner installed an aftermarket stereo, tach, etc, but I really don't think that is it.

The noise is constant when the car is on. Doesn't go away no matter what you do inside the car, not does it ever change.

So I'm thinking something under the hood. But I don't have a clue where to look or what to do. I guess I can replace the wires, plugs, cap, etc, but something tells me that ain't it. It's too constant to be related to speed/revolutions.

Anyone, anywhere, have this problem before?

Thank you.

Brad

Reply to
Repairman54

Might be helpful to know where the noise comes from

Reply to
WindsorFo

most likely. Just turn on the key a little not start, you should hear a short buzz as the pump gets to pressure. if it keeps buzzing you may need to replace it. Sound should be max in the trunk left side behind the tire, take out the carpet to check.

Reply to
jack

Agreed on the fuel pump comments. My '93 has a buzz that is not a high pitch, but lower tone that is from the fuel pump in the back of the car. And as noted in the other post, just turning the key on without cranking the starter you will hear the the noise until the fuel pressure comes up and it will stop. Agreed that if it doesn't stop before starting the car you may have to replace the pump. But after the car is started you will hear the pump run continually because it's going to be working to keep the pressure up. Once when driving and I nearly ran out of gas I could here the fuel pump racing up and down as it was trying to pick up the little remaining fuel.

My experience with audio amplifiers is that many cheaper amps will buzz a lot, but again, if you hear the buzz just turning on the key and not starting the car then you may be onto something. Easiest thing there is just to pull the power on the amp and see if it goes away.

Good luck and let us know if you find it!

mC

Reply to
mC

Wow. Thanks for ALL the sugesstions guys. There's a lot here to look at. Stereo grounds to fuses to the pump. I certainly will look at all the above and let you all know in a week or two.

Thanks again everyone!

Brad

My experience with audio amplifiers is that many cheaper amps will buzz a lot, but again, if you hear the buzz just turning on the key and not starting the car then you may be onto something. Easiest thing there is just to pull the power on the amp and see if it goes away.

Good luck and let us know if you find it!

mC

Reply to
Brad and Karen

It'd be a lot easier if you figured out if it comes from the speakers or not.

Reply to
WindsorFo

Hey guys.

Pulled all the fuses tonight and that didn't help. It's also not the pump, it starts then shuts down.

I took the stereo apart and noticed that the black wire from the stereo was connected to the black/green wire on the car. Could this be the source of the problem? Shouldn't that black wire go to a metal piece?

The grounds on the battery were good. This car has electrical stuff everywhere. It obviously used to run a supercharger and there are more wires for gauges and stuff that you can imagine, under the dash, in the engine compartment. I just noticed a second set of wires coming off the plug to the distributor. They are capped but I have no idea where they once went. The whole car is like that. ARGH!

Thank you again.

Brad

Reply to
Brad and Karen

Okay, I'm only going to try this one more time. Where is this noise coming from? Does it come out of the stereo speakers or from somewhere else?

Reply to
WindsorFo

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