I'm sorry to hear that you're having an issue connecting your iPod.

There would have to be a video signal present to activate the port. You might try connecting it and scrolling through the Edit Input Name (Menu > Input > Edit Name) to see if any of those options will allow the audio through without a video source, but on the 2010 models, I was not able to get this unconventional workaround to work.

In short, a video source of some kind is necessary.