Hello.
I have a problem with my 3. When using my mobile phone as a source for the Aux port inside the armrest sound comes in clear. If I plug the phone in the lighter too (either one) I get a lot of interference. Somebody told me that I Have to take the whole thing apart and separate(or even replace with a shielded version) the 2 cables (lighter & sound). Has anybody else encountered this issue? Any idea how/if I can fix this?

Thanks,

 

make sure it's not the charger itself. I've had a couple chargers that caused noise in the stereo - though only when listening to FM. The aux input noise is a different issue, called a ground loop. Basically there is a different ground point for the radio and the cigarette lighter, and when you plug in your audio jack it connects the two. The difference in the ground is now turned into an audio signal and comes in as noise.

It could be fixed with a different charger (which may happen to be quieter)
It may also be fixed with what is called a "ground loop isolator" though i've only seen them for RCA jacks, and not the 1/8" audio jacks. But with a few adapters and probably $20 later you could have one wired into the input jack.

 

Well.. I did think about this as well... and I found this => http://www.crutchfield.com/S-Cu3VCWl...se-Filter.html

Apparently this is exactly what I'd need but if the problem is the fact that the actual 2 wires are too close together and not properly screened, then the noise filter would filter out from the player to the aux port, when the problem is actually between the Aux port and the Audio Unit.

I tried plugging in a pair of headphones in the mobile while charging and the noise isn't there, so it seems that it isn't the actual phone that's pumping out the interference.

 

I think it's just the electromagnetic field from the power interfearing with the sound wire.
Just like if you were to run your RCAs and power to an amp in the trunk on the same side of the car.

 

To test if it's a ground loop, or the power supply noise - plug in the charger partly so that the outer contact touches the cigarette lighter (ground portion) but doesn't connect to the tip (12V). If the noise is there it's a ground issue, if it is not, it's a switcher issue... and should be there even if the phone isn't attached to the audio system but you are listening to that input with nothing plugged in - aka the electro magnetic noise.

THe EMI noise is what i've had more issues with rather than ground - but if you look at that crutchfield link, the second review is someone with a 3 and it sounds like they had the same issue as you.