Fuel gauge gone a bit mad

Driving today on about a third of a tank, glanced at gauge and it was below red but I knew that unless I had a leak, I had some fuel. few mi9ns later it was showing a third again, then it was empty, then fuel light came on, then it was a third but with light on, then empty with light on...bit kinda erratic! Any likely faults or remedies do yas know?
cheers
Rich

Sounds like either a chaffed wire on top of the tank or the sender itself has gone snafu.

New TDi 300 sender units available from Paddocks about £50+vat

If you take out the sender unit you might see a small bare wire, it's on the moving swing part . this can come away and need soldering. This caused the same problems on my disco.
It's easy to spot and sort out and can save you money.

Thanks guys, where is the sender, is it accessible? I'm in UK, my manual's in Spain (Wife packed, that'll teach me!)

Cheers
Rich

The sender unit is easy to get at, just lift up the carpet in the boot, there is a plate held down to the boot floor with screws (these can be a bit difficult to get out). Take the plate off and you'll see the top off the sender. There are 2 fuel lines and a small plug, undo these, then take off the large ring that hold the sender in place, you might need to tease it with a small hammer, but it comes off easy enough, the sender unit can be lifted out.
You can see the wire on the unit, check to see if it has come away from the solder joints.
If you want to check the gauge before taking the sender out, put a power source to the plug that connects to the sender, the gauge should read full. If so you'll know the sender is faulty.

cheers Pete, ta for info
Rich

Just got round to having a look....when you said screws on inspection plate might be difficult to get out, you weren't kidding! I guess I'm gonna have to drill em out, they're rusted to buggery. Hmmm, first time I've lifted the carpet....should there be all that daylight shining through?!