The PCM supplies +5V reference to the fuel level sending unit in the tank. The voltage passes through the variable resistor grid and is reduced. From there, it goes to the buffer which passes the bounces that same signal back out to the PCM as well as modifies it (buffers it) before sending it to the gauge cluster.

Attached is the wiring schematic applicable to your truck.

 

correct. i cant see what else the pcm would use a fuel level signal for though other than a check guage or low fuel light.

as it stands though you cannot simply remove the buffer and jumper some wires to get a working guage. hence i will be researching the relationship of input to out put to create a circuit that works.

or if your telling me i can jumper for a working guage than i must have a faulty guage?

 

You can bypass the buffer module by splicing the "fuel level input from fuel level sensor" (pin D) to the "fuel level signal to instrument cluster" (pin L) and make the gauge work.