Hello I have a 1998 e350 v10 6.8 extended window van. I was driving on the highway and I hear something kicking under the van and it almost sounded like a flat. I pulled over when it was safe and saw there was a black vacuum line and 2 white lines hanging from the front passenger side under the van by the sliding door. I have gone to ford and a local mechanic and no one can find in the schematic what they go to and what came off the van... any help is appreciated. I have attached a photo

 

Usually a plug doesn't have to go far before it plugs onto something. What you might try is to move the plug around there and look for a control it might have either fallen off from or was pulled off of.

I don't know at this time what it was for without actually looking under the vehicle as you would or you might get a clue if you find something that doesn't work...