Is it my fuel sending unit on my buick century?

My gas gauge is all over the place. I just replaced the instrument cluster. Does that narrow the problem to the fuel sending unit, or could it be something else? 2001 buick century.





Thanks|||It can also be a loose connection anywhere between instrument cluster and fuel tank or a damaged wire anywhere between instrument cluster and fuel tank, or it can be a computer problem (unlikely but possible), or it can be the sending unit (most likely).





To start trouble shooting, plug a known good sender unit into the wiring at the tank. If the gauge becomes steady then the problem is the sender. If the gauge is still flaky then it's the ground (like previous answer), wire, connector, or computer.





It's also remotely possible that your new instrument panel is also bad - I've had this happen to me - my junk yard part had the same failure!|||gm is good for their floating guages, my olds does the same. the only time i can actually tell how much gas i have, is when iam on a level surface.|||most likely its the sending unit, it also could be an intermittent ground problem