What is going on with my AUX input?

[bairjo]

Originally Posted by CTScott

It is likely the aux port. Besides passing the audio signals it triggers a switch within the jack that tells the head unit to enable aux mode.

I'm at work right now, otherwise I would go out to my car to see if this makes any difference....doe the audio source need to be turned on in order to trigger that switch or does the fact that a plug is inserted and making contact do the trick?