Where do you located the wiring schematic for a 1985 Ford F-250 Pickup specifically looking for wiring harness to the electrical fuel pumps dual tanks and relay?

beleive it or not there is only one fuel pump for both tanks. the fuel pump should be located under the truck on drivers side running with the frame rails. the fuel pump relay will be located under the hood usually on the drivers side there will be a lot full of relays there. im not sure what the truck is doing im not sure on that year but sometimes they put iin fuel shut off switches. im not sure where it is located in that year you can call your local ford dealer or part store they can tell you. your local part store can also sell you a manual that will show you the wiring diagram it should be around 15-20.00

Actually No on the 85 and 85 models there are two fuel pumps one in each tank and on the rail is an electronic tank selector unit. They are not fun when they go out. you have to wire in a new plug