Section 10-01B: Fuel Tank, Filters, Tubes and Fuel Pump, Diesel Engine | 1996 F-Series and F-Super Duty Vehicles Equipped with Diesel Engines Workshop Manual |
The six-port diesel fuel valve is powered by a small electric motor which opens and closes the valve ports. The supply and return ports for either tank open and close simultaneously. The valve is shifted to the front mode (that is, the front supply and return ports open to the engine supply and engine return port respectively) by applying a positive 12 volts to terminal 2 and ground to terminal 1. When the valve reaches the front mode position, an internal switch opens the circuit and stops the motor. Returning the valve to the rear mode is accomplished by reversing the current: positive 12 volts to terminal 1 and ground to terminal 2. Terminals 3 and 5 connect to the front and rear fuel tank senders respectively, and terminal 4 feeds the fuel gauge.
In the front tank mode, an internal switch connects terminal 3 to terminal 4, thus supplying the front tank sender signal to the fuel gauge. Terminals 4 and 5 are connected in the rear tank mode. Therefore, a change in the fuel gauge reading (assuming at least 1/4 tank fuel level difference), means that the valve has shifted.
| Item | Part Number | Description |
|---|---|---|
| 1 | — | Frame Doubler (F-350 Chassis Cab Only) (Part of 5005) |
| 2 | 9F271 | Six-Port Fuel Tank Selector Valve |
| 3 | 5005 | Frame |
| 4 | — | Electrical Connector (Part of 14405 Wiring Assembly) |
| 5 | N605905 | Bolt |
Electrical current is supplied to the fuel tank selector switch from the fuse panel when the ignition switch (11572) is in the ON position. This current goes through the fuel tank selector switch directly to the motorized fuel tank selector valve.
With the fuel tank selector switch in the front tank position, current is supplied from the selector switch to terminal 2 of the fuel selector valve. The ground path is completed through terminal 1 of the fuel tank selector valve and is grounded through the selector switch. This causes the fuel selector valve to rotate internally, opening the ports to the front tank position which allows fuel to flow through the fuel tube to the engine.
With the fuel tank selector switch in the rear tank position, current is supplied from the selector switch to terminal 1 of the fuel tank selector valve. The ground path is completed through terminal 2 of the fuel tank selector valve and is grounded through the selector switch. This current path causes the motorized valve to rotate internally, opening the ports to the rear tank position which allows fuel to flow through the fuel tube to the engine.