F 250 4WD Pickup V8-460 7.5L (1984)
Testing of warranty returned fuel selector valves used on 1983/84 Econoline and F Series vehicles with the 7.5L engine indicates that selector valves are
being replaced unnecessarily. The procedure listed below should be followed when a selector valve concern is suspected. Use of this procedure will
eliminate unnecessary selector valve replacement.
Power is supplied to the fuel tank selector switch from the fuse panel when the ignition switch is in the "ON" position. This power goes through the fuel
tank selector switch and then directly to the motorized fuel tank selector valve.
With the fuel tank selector switch in the front tank position, power is supplied from the selector switch to terminal number 2 or the motorized fuel valve.
The ground path is completed through terminal number 1 of the fuel tank selector valve and is grounded through the selector switch. This causes the
valve to actuate opening the ports to the front tank and allowing fuel to flow through the fuel line to the engine.
When the fuel tank selector switch is moved to the rear tank position, power is supplied from the selector switch to terminal number 1 of the motorized
fuel valve. The ground path is completed through terminal number 2 of the fuel valve and is grounded through the selector switch. This current path
causes the valve to actuate opening the ports to the rear tank and allowing fuel to flow through the fuel line to the engine. The valve also directs excess
fuel which is returning from the engine to the same tank that fuel is being pumped. Fuel valve terminals 3 and 5 are connected to front fuel tank sender
and the rear fuel tank sender respectively. Terminal 4 feeds the fuel gage. In the front tank mode an internal switch connects terminal 3 to terminal 4 thus
supplying the front tank sender signal to the fuel gage. Terminals 3 and 5 are connected in the rear tank mode.
Power is sourced to the chosen tank electric fuel pump by the fuel pump selector relay. Terminal number 2 of this relay is electrically connected to
terminal number 2 on the fuel tank selector switch. (This causes the front
pump to run only when the front tank is selected and the rear pump to run only when the rear tank is selected). Relay terminal number 1 is connected to
ground to complete the relay coil circuit. Relay terminal number 4 supplies power to the front tank pump and terminal number 5 supplies power to the
