My stereo has this peculiar noise coming through.

1. I checked all the grounds in relation to the headunit and speaker connections. Looks fine.

2. Replaced door speakers. Sound still present.

3. Replaced Headunit. Alpine9801. Sound still present

4. Ran new power&ground wires from battery to HU. Sound still present.

5. Disconnected alternator power wire. Sound still present.

6. Engine on or off sound still present (with alternator power wire connected and disconnected). Radio must be on tho.

7. Sound seems to coming out at a fixed volume. If I turn up the radio the noise gets drowned out.

8. Sounds is like the ringing of a phone. Doesn't seem to increaes or decrease with engine revs.

9. Sound is sparatic in interval. Comes and goes. If I open the driver door, turn cruise control on, foglights, or just about any electronic equipment it sometimes triggers the sound. But no single piece of electronics triggers the sound.

Sorry about the length and this is probably my 3rd or 4th post about this topic. Really seems as tho taking it to the dealer is the only way to go, however, if its a loose ground or disconnected wire somewhere I am hoping someone might know. Maybe suggestions or please reply with similar experiences and solutions. Thanks.

did you upgrade the ground to the battery, chasis, intake etc? I had terrible noise in my car also but ran 4ga from batter to HU/amps for both ground and power solver the problem.. also if you have external amps make sure they are grounded to the same point as the HU. Its really strange that there is noise there when your car is off however.. you might want to put a meter on the battery and see what its doing.. could be the battery. or a loose/pinched speaker wire somehwere.

Yeah pretty strange noise, I tell ya. Everyone on other threads agrees that it is probably a ground or pinched wire. Dangit. I knew I shouldv'e chosen Electrical Engineering instead of Developmental Math. Thanks for the info elsanto.