Gas Guage

I have a 1990 GMC c1500 truck. The gas guage hasent been working for a while now, so I dropped the gas tank and replaced the sending unit and made sure the wires were hooked up including the groung wire. Then I filled it up with gas and it barely moved and still doesnt work. All the wires seem fine and undamaged all the way up to the firewall. Is it the guage it self thats bad?

Those tank gauges go bad often , you should get it checked. When you have your tank down again to take out the gauge to check it, try it before you put another one back in. You don't need fuel to see if it works. Turn key on , hook up your wires and have someone watch your interior gauge as you move the tank gauge by hand. I did this last week to my brothers truck, his tank gauge was bad.