Sound coming from speakers with radio off

[ChairmanRon]

I get an intermittent noise from the speakers while the radio is off. The frequency is in direct proportion to the RPM of the engine, and unaffected by whether headlights are on or off. Any ideas as to cause/cure? Mine is an 03 986.

Thanks!
Ron

[tonycarreon]

i can't say exactly, but the wires are (probably) unshielded so any radio interference will mess with the speakers producing sounds.

i couldn't keep my old iPhone / 3Gs in the cubby because when it would jump to the EDGE network my speakers made some funky noises even if the stereo was off.

do you have the rear speakers?

probably electrical interference by the alternator, not the engine...

of course i could be talking out of my a$$ and be totally wrong.

my '88 ford tempo did the same thing


http://www.sacskyranch.com/altnoise.htm

[Stiletto Pat]

Ron,

I have an 03 986 S with a CDR-223 with the optional Bose System. I've experienced a situation where I was listening to the radio, stopped the car and turned it off and removed the key, and the system continued make sound - changed from music to some type of static, popping and thumping. Continued for a while, but eventually stopped. This was a one time occurrence, but obviously, it does happen on the Becker radios...

Pat

[thstone]

An intermittant noise proportional to the RPM of the engine implies a possible shorted wire making intermittant contact with the chassis creating a ground loop which couples to the alternator.

This page might be helpful: How To - Car Stereo - In Pursuit of a Noise-Free System: The Ten Commandments of Noise Prevention