So the  next problem to fix!   I have been driving the truck down to 1/4 tank, and I'll fill it up.  Every so often the gauge will read empty and stay empty for while, and then come up to full.  No it stays on empty even after I filled it up all the way, topping off to make sure..  

Is there a loose electrical connection?,  or is the tank sending unit bad?    I looked on the past forums and could not find anything similar,.

 

Thanks.again folks.

I would guess your issue is in the wiring.  

 

I would check the junction above the drivers front tire.  All the bed wiring goes through that junction.  It can get pretty nasty due to all the road stuff that cna get kicked up.

There is only one wire to the PCM for the fuel gauge. The other is a shared ground for the tail light and such. My bet is on the single wire to the PCM. Should be able to turn the key on and probe for a 5V signal. (Educated guess)

22 hours ago, GSX455 said:

No it stays on empty even after I filled it up all the way, topping off to make sure..

 

It's possible the float is stuck along the wall. Loosen the sender nut and rock the sender carefully left to right and listen for the arm to tap the tank wall. Then split the difference for center.