Ive looked at some of the posts on this problem but cant find the fix to my problem so here goes, 1987 defender fuel gauge suddenly went to full turn ign off and it goes back to empty,so I fitted new sender unit and it still does exactly the same, the low fuel light still works ok so could it be a broken wire between the gauge and sender unit, any info on this one please thanks Geoff.(please dont ask me to use one of those multi meter thingy bob things cos I havnt got a clue)

Sounds like yer sender gauge wire has rubbed through/shorted out. Seeing as you can't/won't use a multimeter I recommend completely replacing your electrical wiring loom one wire at a time until it sorts your problem.

Right - follow your tank loom up to the bulkhead, it ought to be connected by a 2 pin connector to the bulkhead harness and a single black negative will go to an earth point. Pull the two wire connector from the bulkhead connector and see if the gauge reads empty.

If it does then as said above there is a short in the wiring down to the tank or there is a connection problem at the sender.

If it still shows full then the fault is with the gauge or main harness/dash wiring.

Cheers for the info Disco,I can usally sort it when Its told like that (someone who speaks my language)