I've searched quite a bit, and haven't seen this problem. My 2004 RX-8 was purchased from the original owner in April, and he had installed one of the IPOD Aux-in kits, which plays through the Tape input. I've just purchased a portable GPS/MP3 Player, and when I power it through the cigarette lighter sockets (either one) I get this intermittent popping and buzzing through the AuxIn. This happens even if the engine is off, in accessory mode. If I power it from a stand-alone car charger that has a cigarette lighter port, I get no noise.

All the posts I've found have been about alternator whine, which changes with RPMs. But since mine happens when the engine is off, I'm not sure if a ground loop interrupter will help. Anyone else experience this problem, or have any suggestions about what I need to do before I tap the cigarette lighter power line for a more permanent installation?

Thanks...

 

http://www.finishlineperformance.com...31-08-1997.pdf

 

Thanks, Mazurfer. I even have one of those Radio Shack filters somewhere around here, Now to find it...

 

No guarantees, but worth a shot.

 

Well, the news is mixed. The Ground Loop isolator does seem to kill the noise. However, the sound coming through it seems to be "out of phase", like the polarity of a connection is wrong/switched.

I don't think the isolator is the problem, though. Both the AuxIn connector coming from the Head Unit and the Garmin headphone jack are 4 conductor jacks (on an Ipod, I think the 4th conductor is transport control?). But my adapters to go from 1/8 headphone jack to the RCA connections required by the isolator are 3 conductor (regular headphone jacks). I think that in plugging the 4 conductor plugs into the 3 conductor adapters, the some poles are getting shorted.

So, I guess I need to find some adapters that properly convert 4 pole to 3 pole 1/8" headphone connections. The search continues.

Thanks again for your help!