Repairing fuel level sender?

[Duckham]

My fuel level sender has stopped working as the very thin resistance wire has broken at one end of the coil / winding.

I would prefer on principle to repair rather then replace (especially with the generic mechanism that seems the only option) but can't think of any practical way to tackle this. Any suggestions?
Search led to a comment that Nisonger in the US refurbish senders, but I am in the UK.

TIA
Joe

[cactusman]

It may be possible to carefully undo the last turn near where it broke and then re-attach. Removing one turn will not significantly alter the way the gauge reads. Only issue you may have is that if the wire is nichrome resistance wire....I think it is....then it may be difficult to solder... Worth a try...

[PeterCrespin]

That was going to be my suggestion. You could maybe adjust the wiper contact so it doesn't quite sweep full width and make the new connection with a small rivet. I'm in the UK until Thursday Joe, and back around the 28th for funeral number two, so if you want to post it to Naomi in Cheltenham I can handle the New York end?

Since Nisonger as basically Smiths licensees, have you tried the 'original'rightd holders, Caerbont Instruments near Bridgend? I'm due there to pick up a D gauge in the 'near future'.

[Duckham]

Thanks, both.
I could not move the winding assembly and the wire itself seemed to be firmly attached to the core as if glued in place so I'm not sure I could even undo one turn.
The wire is so fine I didn't think I would be able to successfully solder it even if it was copper, so a mechanical connection would be better - but the if that is what you are thinking with the rivet, Pete, there really isnt any room to do that.
I'll have another look at the weekend and also get back about Nisonger, Pete.

BTW although there was nothing about repairing fuel senders I did see Caerbont now provide matched oil pressure gauge and sender that was the subject of a thread some time ago. https://www.smiths-instruments.co.uk/jaguar

Joe

[abowie]

I have tried this a number of times without much success.

If the arm won't move it may be that it is corroded where it pivots.

You can buy nichrome wire but you need one that has the same resistance per inch or your calibration will go out the window.

You could fit a potentiometer and calibrate it to the gauge but you might find it hard to get it properly calibrated at both ends of the scale.

For the price buying a new one is probably your best option.

[Duckham]

Thanks Andrew. I tried to apply solder to the broken wire with no success at all, possibly because I cant think how to clean the surface of something so fine.
Life is too short to experiment with rewinding and Nisonger haven't responded to say if they can fix it, Pete, so I think it is time for a generic replacement.
Cheers all
Joe

[PierreW]

Only issue you may have is that if the wire is nichrome resistance wire....I think it is....then it may be difficult to solder... Worth a try...
[/quote]
Nichrome wire and all nichrome alloys like li-ion battery shells can easily be soldered with tin solder if you use phosphoric acid as solder fluid :-)