F 350 2WD Pickup V8-6.9L DSL (1983)
Figure 17
Figure 18
The 6-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 number
2 and ground to terminal number 1 (Figures 17 and 18). When the valve reaches the front mode position, and internal switch opens the circuit and stops
the motor. Returning the valve to the rear mode is accomplished by reversing power: positive 12 volts to terminal number 1 and ground to terminal
number 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 and
internal switch connects terminal 3 to terminal 4 thus supplying the front tank sender signal to the fuel gauge. Terminals 3 and 5 are connected in the rear
tank mode. Therefore, a change in the fuel gauge reading (assuming at lease 1/4 tank fuel level difference), is a positive indication that the valve has
shifted. For the following diagnostic procedures, both tanks must contain some usable fuel.
OTHER APPUCABLE ARTICLES: None
WARRANTY STATUS: "INFORMATION ONLY"
