Audio Systems: Ford RSE w/aftermarket head unit, pin pricks, ford excursion

Question
Hi, hopefully you can help, I have an 2005 Ford Excursion w/rear ent. system. I am attempting to install an aftermarket indash DVD/monitor. I do not need the front to play on the back or the use of the factory speakers to play audio for the rear dvd. I just want the rear dvd to play and audio for it to play over the existing wireless headsets. The factory head unit has two plugs on the back, one is the standard 98-up ford wiring plug, the second is for the rear dvd. If you could offer and help that would be great, hopefully you just have a plug that will fix it. Thanks Again Dave


Answer
so let me get this straight. basically you want your new dvd to take over as the main player in the car using the speakers and such.  and the rear one basically just needs power to work and that's it really?
If so, in that bundle that goes back to the rear player there should be 2-3 wires that power it. you need a meter to find out what's what and the best way to tap them probably is something like this:

http://www.radioshack.com/product/index.jsp?productId=2104093

it allows the existing wire to not be cut and you splice a new one along side it.  if you ever want to put the system back the way it was you just unsnap the connector and there's only little pin pricks into the wire that you can put tape over or even just leave alone.  

Basically I would recomend you get a meter to test those wires in that connector.  it actually would be much easier if you can find the other end of that connector where it attaches to the rear unit (connector in the rear, not the connector in the dash), then connect up the one in the dash and measure the connections in the rear plug one by one.  (if you need step by step instructions let me know) but first things first, get a meter and see if you can find the rear plug.
Let me know, this shouldnt be that hard!