Where is fuse for fuel gauge located and what is it's name for 2003 Pontiac grand prix

It only goes to empty if I'm on a incline. Other than that, it stays full.

So does this mean it's still a bad ground? And how hard to fix this?

So where is this plug located? Maybe I can unplug it and clean it?

Thanks for everything Jim your an amazing help

So it wouldn't be in the trunk on this make and model I'm guessing?

That would be too easy. No, its underneath the car.

Maybe easy for you, but I have never worked on a car.

My fuel gauge reads full and empty is that a relay bad ground

More likely its a faulty sending unit which is inside the gas tank. Obviously, check the wiring first, but a bad ground would show either full or empty all the time regardless of whether there's fuel or not.