Petrol tank sender unit

Anyone repaired one? At the moment my tank is permanently full! 8O

I've confirmed the gauge itself is ok.

 

I rewound mine to suit a different dash. I would class it as repairable, depending on your skills.

Done any fine electrical work before?

 

errr no but happy to have a stab...its buggered anyway!

 

The workings are quite simple, just a wire wound resistor and a wiper arm.
Take the sending unit out and remove the cover. It has some tabs bent over holding it in place, carefully bend them out with a small screwdriver or knife blade. Underneath you will see the resistor and arm. Get some 600 grit sandpaper and clean the arm and resistor face that contacts the arm. Also clean the ground connection for the wiper arm(its a small brass spring off to the side). Get a meter and connect one to ground(sending case) and the other to the wire that goes through the plastic washer. Move the float through its movment and you should see a gradual change in the reading from 0 to about 300 ohms. If the meter readings do not change consistantly or it goes to high readings clean again.

 

i just tested mine after it got a good dose of the evapo rust and im not getting a reading sometimes i wonder about my mutimeter though cause its from harbor freight....

 

many thanks mlew