What has to be hooked up to run the engine in a 2004 XLT?

[tsamrein]

I am using the frame and drivetrain from rusted out 04 XLT for a Rat rod project. I removed alot of stuff and now cannot get the expedition to start. I have removed the back half of the body and the floor up to the front seats. The roof is gone so basically it is just a frame and the front end. Not sure if I just removed a ground wire that i need to reconnect. Just looking for some input.

Thanks in advance for any assistance.