1972 notch fuel sender query

Hi all, just wanted to discuss the following with those that might know from a non mechanical vw owner - the fuel gauge in our car has been inoperative since we bought a short time ago - when we purchased, seller gave a replacement which we have fitted and had showed some signs of working but has since failed. Can someone please advise potential causes of this Prior to a visit to the auto electrician? My main question is can these devices be repaired or is it a matter of replacement? If is likely replacement does anyone know suppliers in AUS?

forgive the non-tech terms, from memory is a cylindrical aluminum tube bolted onto the top of the tank..

appreciate any advice..
Thanks Heath aka abandpops

Before doing the tests below check all the connections to the sender, should be clean and firm, ther should be two wires, one from the sender to the guage and another from the top housing screws to a good earth.


You can test the sender by checking resistance through the unit, with a multimeter, remove the sender from the tank and put one lead on the top terminal, the other on the top housing somewhere, then slowly immerse the tube into a bucket of water. The resistance should change as you lower the sender in.

The guage can be checked by earthing out the wire fitted to the senders top terminal, the guage should go from empty to full in the blink of an eye.

thanks 66brm..appreciate the reply will give it a go...