Does fuel pump have anything to do with fuel gauge

Sure sounds like a faulty sender in the fuel tank...

Way to check would be to remove the wiring from the sender when tank is low and gauge is playing up at half way , if the gauge falls it's the sender, if not it's the wiring...

Sounds like a faulty sender unit in the fuel tank...

Your fuel pump assembly located inside the gas tank has a float that measures how much gasoline is in the tank. False readings means the fuel pump assembly needs to be replaced.

One of the wires to the sensor is touching a ground. It may be getting pinched

hi,

sounds like the sending unit rheostat(sending unit) has a bad contact or break in the resistance wire. inside the tank theres a float attached to an arm that goes to a small rheostat, like a volume control on a stereo. the rheostat is sending a scratchy signal or no signal to the computer and your getting these readings. that part is inside the gas tank, the part usually comes integrated with the fuel pump. the gas tank has to be lowered to fix it.

jm

I would bet the sending unit is bad but lets check it, a good test i use is that i have a used sending unit i connect to wiring to test the gauge and wiring, if the gauge moves when i move the testing unit then i know the gauge is good and the wiring to, locte the connector at fuel tank, and unplug it, this will be the one the leads to top of the tank and the connector will be on the side be the frame on drivers side, the way you know you have the right connector will be the truck will not run as this connector has the sending unit and pump wires in it, if the gauge goes to full then you know the wiring is good and the gauge is good, you can jump the two wires and gauge should go to full also. the problem is you must get the right wires for sending unit or you may pop fuse, let me see if i can get you a wiring diagram or just do the full test by unplugging connector.

Okay, your sending unit has a yellow and white wire, thats the sending unit wire, the other is a ground and we wont worry about that. so if you want to see if gauge will go to empty or full just unplug connector and gauge will move to full then if you take a wire and jump the yellow wire with white stripe to a good ground the gauge will go to empty, the thing is your gauge is on empty so sending unit may be grounded out, good day

Fairly common problem with GM vehicles. The sending unit in your tank has a small circuit board that an arm is attached to which moves up and down according to your fuel level. This circuit board and arm are not making good contact. Unfortunately the only good solution is to replace this part.

sounds like you probably need a fuel level sender. it's located in the trunk on the right hand side attached to the fuel pump. I got one on ebay for about 20.00, but you might as well replace the fuel pump while you're at it, as it can go bad with time.

remove wires on tank unit ,multiplug and plug in another one and manually try that ,sure thats the problem the relay falling apart has nothing to do with problem of fuel gauge

It could be the fuel sending unit.