What wire do I connect the illumination wire to?

I am installing a Song Xplod CDX-GT440U. The wire connection that came with the receiver has 13 wires. I purchased a harness that has 14 wires (my car also has 14 wires including the orange illumination). All of the wires are connected except for the illumination (orange) wire. What wire do I connect the illumination wire to or what do I do with it? All wires are connected except for that extra one.