Strange fuel gauge activity

[fiddler]

I have a 1974 Chevy C10, (half ton stepside, 2 wheel drive).  I have a replacement fuel gauge from  .  The gauge reads relatively correctly, (slightly above full when full).  When I turn off the key, instead of remaining where it was it climbs as if the sensor line was open and there was voltage applied.  I have another fuel gauge from a 73 model that works and does not do the described behavior.  (I would use it but it does not have a window for the brake warning light).  When i turn the key back on the gauge goes to the correct position.  I cannot figure out what is driving the meter when the power is off.  Anybody seen such bizarre behavior on your fuel gauge??  Thanks for any response. 

[bd]

It is probably residual magnetism interacting between the gauge coils and gauge frame and should be of no significant concern.

[fiddler]

Thanks much!  I will go with that until I run out of gas and the gauge is telling my it still has half a tank.  That is what AAA is for...   

[bd]

LOL.  If there is no power to the gauge (ignition off) and the dash grounds are healthy (no floating feedback loops), what else do you propose?  Personally, I would find it annoying and might try to degauss the gauge or substitute another, but it should not cause a problem, otherwise. 

Who knows what substitute materials, processes and quality controls have been employed in the manufacture of offshore-sourced components?  You could try contacting the vendor.  I suspect 50/50 odds that a replacement would function similarly.  In the meantime, be sure to carry your AAA card and a cell phone.   

[fiddler]

So it works great all the way to empty.  I filled at empty and it took 13 gallons plus.  That's close enough for me.  Usually I fill just below half....  Thanks for your inputs.