I also posted in the van forum...
I have a 2011 E-350 van ambulance. I am trying to make the fuel pump run continuously to drain the tank, due to 20 gallons of diesel being added.
Jumping the relay yields the same results....fuel pump only runs a couple of seconds. My scanner is not updated to do anything over a 2010, so I can't command the fuel pump on that way.....Any ideas?
Can't siphon either...

 

The fuel pump only runs for a few seconds to prime the system, not sure how to make it run continuously. But it's designed to only run a couple seconds when turned to "Start"

 

It runs continuously when in crank position, but I don't want to go that route.....trying to unplug the fuel pump and power it that way, now.