oneloveofboard

Can anyone help me on this, as im stumped.

I have a 2005 LINCOLN NAVIGATOR and I have changed the head unit to an after market unit due to me being in the UK and using PAL/different navigation dics.

I have managed to connect up the AMP and SUB without any problems, all the speakers are working and I have managed to power up the roof mounted DVD player and I have fed a signal to it via the AUX input.

But when I want to use roof mounted DVD player as a stand alone player, ie a DVD playing in the back and the radio/sat nav in the front, there is no audio coming from the roof mounted DVD player or through the wireless headphones or from the headphone jack in the centre consol.

If I put the factory head unit back in then the wireless headphones pick up the audio from the roof mlunted player and headphone jack works fine, so I am assuming there is some kind of loop system which connected to the old head unit that needs connecting to something or looping back on themselves to get the audio to work ?????

If anyone has any experience on this or can help me get it working please let me know as I am constantly listening to my kids HighSchool Muscial everytime we get in the car and its driving me insane !