1998 Ford Expedition EB edition problems?

My husband just changed the plugs and wires in a 1998 Ford Expedition. He is a decent mechanic, he know his stuff but unfortunately this one is puzzling him. After this simple operation that he has done hundreds of times, the power to the vehicle is completely gone, the truck will not start. He has gone over and over everything that he has done with no problems. He replaced the solenoid and checked all of the fuses the battery and fuel pump. We have googled for problems on these trucks but it comes back to nothing. The only thing we can think of is the PATS (Pive Anti-Theft System), and I have found instructions on how to reset the keys but with no power to the entire vehicle we a unable to do this as well. Any ideas