http://www.crutchfield.com/p_120705520/Rec...re-Harness.html
This was the one I used...I got it free form Crutchfield when I ordered my head untit from them. You will also need an antenna adapter. If you log in to Crutchfield it will tell you everything you need even if you don't buy from them. Any 2003 up Ford/Lincoln wire harness will work.