Ignition noise

[grankin]

I finally got tired of using the aged iPod in the iPod dock, for it fails to understand 'shuffle' when hooked up that way. So I got me a long cable with audio plugs at each end and a plug for the 12V 'cigar lighter' with a 5V USB connection. Now I can use the iPhone 4S as the sound source through the 'aux' input, see what's being played on its screen (it grasps 'shuffle' very nicely), and keep it charged.

Here's the problem: it 'sees' ignition noise (rises with revs) through the 12V socket (not through the 'aux' input). Not loudly, but enough to be annoying in quiet sections of tunes.

Here's what's odd: I have a 20-year-old Porsche, where I hook the phone up the same way. NO ignition noise. None.

I figure a low-pass R-C filter (allowing only DC through) will clean it up, but executing that notion is outside my expertise. Anybody have a good idea?

 

[PoRsCh3fReAk]

Deff would be interested to find out what people say. I have a cigarette lighter charger for my phone and I get the noise very loudly picked up through the speakers. Think there's a high doubt of finding a solution. Running a frequency throughout the system. My old camry did that same thing

I was curious in knowing if anyone found a way to make a female to make iPod cable and if it would charge through the center armrest as my iPhone 4S doesn't seem to register on the console. I know it's not my forum but if anyone knows how that works if appreciate the know how

 

[leftcoastR32]

That's weird...I have no probs with my VW. But my Nissan truck is so anoying, bzzzzzzz all over the place. Idk what's up with the v-dubs though. GL

 

[Timpanogos Slim]

it's not necessarily ignition. could be the fuel pump. Anything that works harder as the car revs faster.

One of two ways to fix it.

It's either a ground loop, and you need a ground isolator like sometimes get used between amps and stereos. Basically AC couples the signal.

Or it's noise on the power lead itself, in which case you need a dc filter behind where you're getting power from.