fuel gauge not working on my daewoo lanos 1.6i sx

Probably the sender unit in the tank. Find the lead to the fuel level sender unit in the tank, connect the lead to earth and turn on the ignition, if the gauge now reads full the fault is in the sender unit, if there is no reading or movement of the gauge then the fault lies elsewhere.

Reminds me of our old Avenger (first car we bought, it cost £50). The fuel gauge never worked, and we carried around a plastic pipe to stick in the tank to check the level. When I finally got round to looking at it, I took the driver's seat out to find that the loom went under the lug where the seat was bolted down, and they'd just crushed it. You can only laugh...

I had a car that to make the gauge work had to have a bucket of water thrown over the tank filler pipe and rear wheel arch every few weeks in dry weather.

Excellent. I can't help wondering how you found that out.