Gas Guage wont Work on instrument panel

Gas Guage wont Work on instrument panel

I have a 2000 gmc Sierra 2500 6.0 and I'm having problems with battery gauge flickering and my gas guage will work and then just stopped working altogether and now it has gotten to where it won't work at all, do you have any advice or know what I should do because I've already checked fuses and ground wires and that doesn't seem to be the problem