Stereo buzzing when engine running
 

Greetings,

I've changed out my stock infinity system today because there a loud buzzing noise. After I installed a new Kenwood head unit, it's doing the same thing. I found out that it only does this when the engine is running. Another funny thing is that by accident, I turned on the hazard lights and it buzzes when the light come on, off when it goes off. I'm thinking it's a ground wire loose somewhere. Any suggestion will be greatly appreciated.

Thanks,

John

Update,

When I turn the engine on, it starts buzzing. I turn it off and keep the key in ACC, it stops buzzing after 5 - 15 seconds. I turn the engine back on, it starts buzzing again and after a little while, it stops. When there is no buzzing, I press on the button to roll down the window, there's a quick buzz. This happens when I press almost any electrical button. One weird thing is that when I turn on the hazard lights, it buzzes when the light comes on and no buzz when it goes off. Let's call it a buzz blink is happening.

You have a buzzing on the 12 volt line
Something is causing this oscillation
You can either track the source of the oscillation or
Put a filter on the power source to the radio.

Good luck

I also have a factory amp under the driver seat. That could also be the culprit. Do you know of any good filters?

Best one is a separate power supply.
But, no. I am not an audiophile.
And you're right. It could be the amp??

Good luck.

Got it. I also consulted a friend who's an electrical engineer and he gave me this massive capacitor which barely fits under the seat. I'll have to try that. Too cold here in VA to mess with the stereo. I'll let you know if that worked. Thanks for your help avisitor.

With a capacitor that big, I'd be afraid that it would blow up with me sitting on it
Then you would have one of those scenes from 007 james bond
The guy ejects out of the car and the car explodes ... lol

LOL. It's a rotel 15000 uf 80v dc capacitor. I hope it doesn't blow up on me. I dont want to be ejected through my sunroof. He told me pros use it for concerts stages and so on for noise filtering. I'll have to put a lotof electrical tape on the wire connectors.

This doesn't have to get complicated, but maybe a little background might help.
RFI, Radio Frequency Interference, used to be a problem many years ago and one of the solutions was to install spark plugs with internal resistors.
Just about all spark plugs sold today have that internal resistor in them.
There also was a problem coming from the old type generators for the charging system. The way it was corrected was to install a simple small capacitor on the positive supply to filter out the interference.
It was easy to purchase a small capacitor from any auto supply store or electronics supplier. It is not such a problem these days and not sure if auto supply stores still sell them. The capacitor is about 2 in long and about 5/8 in diameter with a short wire coming out of the metal case. The case gets mounted to a good ground and the short wire connects to the positive supply to the radio. It is that simple.
Now you know what you need and where to place it, it should get rid of the noisey static problem.