I've just recently bought my xg ute and the fuel gauge is stuffed,it says it's 100% full for a while even if it's close to empty then eventually it just drops and sits on empty,sometimes it drops out when I hit a bump but other times it's on it's own,I was wandering could the cluster be faulty (odometer also doesn't work) or the sender unit in the fuel tank,if so any info on where to find one or one that would work would be appreciated

Check your earth cables to the body in case there's rust/oxidation affecting the connections. If you remove the fuel sender from the tank, you can test the resistance across the two plug pins. It should read 0 ohms at empty and 180-200 ohms when full. After that, I'd look for a secondhand cluster.

From you saying the needle on the cluster goes to full and then your getting power to the cluster and the gauge in the dash is working, pull the screws out of the tray that cover the fuel tank and pull the sender unit out the tank and make sure the float arm hasnt broken off the sender unit.