All it does on the diesel's is hold the fuel stop on the pump so it will not start and Does no give you a 12v feed to the starter switch , i have to do this on my step dads transit for the same reason , go to the back of the ignition barrel and there are around 4 to 6 wires on the back of it . find the wire that gets 12v when you have the barrell in the crack position . tap into that wire ,then run a wire from there to the starter motor but make sure you fuse it . Then find a wire on the back of the barrell that is live when the ignition is on position 2 (when all dash lights are on ) and goes out once you take the key out , tap into it and run another wire to the fuel pump stop wire (12v wire not the earth) and fuse it some were , with that the van will start . Rich.