So I've just purchased a stagea, one of the issues was the fuel gauge showed full all the time, but the fuel low light would still work
what u need
Philips screw drivers
2 bench powersupplys or a powersupply with 2 adjustable outputs
I removed the steering coloum covers 4 screws
Removed the dash cluster cover 2 Screws up the top
poped the rear windows spray and the demister buttons and undid plugs
removed the dash cluster
removed the front plastic overs
and then removed the fuel gauge
I hooked it up to a powersupply on the bench to check that it worked
there is a ground and to signal wires
I put 12 volts to first single gauge went one way and put 12 volts on the other signal and went the other, so I new my gauge was working!
The gauge works from the difference of the 2 signals , if both signals has 12 volts the gauge should read in the middle or 1/2 tank, this was my first problem, as the gauge when having 12 either side of it was still reading over full
We moved the needle down till when we put 12 volts both side it sat at half a tank, so this has calibrated the gauge on the bench so it's sitting in the correct location.then changing the difference between the volts the gauge then started going up and down! I also kepted the voltage very low and bumped a bit of current up, this would also give the copper a good buzz in case of corrosion etc
put the gauge back, and is working well!