back to factory radio

I have a pioneer avh 4300 unit in my truck now. i had a place install it for me. I am trading in my 2005 Ford Explorer for a newer one tomorrow. I want to keep my pioneer and put the oem radio back in there. now to do that all i need to do is unhook the wiring harness that plugged into the factory harness and plug THAT factory harness into the factory radio correct? i also noticed there was a light green wire coming from somewhere else. i found out after doing some research its "Car Radio Battery Constant 12v+ Wire: Light Green". what do i do with that wire?

The light green wire you speak of is the parking brake wire of the pioneer unit. It should run to your parking brake. Cut it and insulate the end that goes to the vehicle.

thanks for your reply. i dont need to worry about that wire to put my factory radio back in? just insulate it?

It is not needed by your factory radio.  Just insulate it = cover the end of the cut wire so it can not come in contact with ground.  If it does come in contact with the chassis of the factory radio or the chassis of the truck, it will illuminate the brake warning lamp on your dash.