The fuel gauge did not work when I bought the car, but it was a project on the previous owner’s list. He had a replacement sending unit in the trunk of the car. It’s a little tricky to know when to tackle the replacement—the gas tank has to be less than half full, otherwise gas will spill out when the old unit is removed. But, how to know what’s in there if the gauge is not working? If you can figure that out, the rest is pretty simple.