89 F-150 The yellow wire to relay is always hot. The brown wire coming from computer is hot when key is on. What about turning that brown wire into an on off, with a toggle switch ? The other wires are not really necessary, are they ? One goes to the E.E.C.

 

It is wired that way for safety. If you hit something and the engine dies then the fuel pumps will turn off in one second.
The red wire goes to the power relay, tan wire with a green stripe to the computer, the brown wire to the inertia switch and the yellow wire to the starter solenoid.

 

The red wire that goes to the power relay. Am figuring that it supplies power from the fuel relay to the power relay, right or wrong ?

 

Wrong, the power relay supplies the power to the Red wire.
The Red wire supplies power to the coil of the fuel pump relay, all of the fuel injectors, the computer and a lot of other solenoids.

 

The power relay is operated by the Ignition switch:



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