Some..... (I'm not sure all) APU oil quantity transmitters are basically potentiometers.
We found 4 VDC excitation voltage present on one end. Total resistance across the pot was 260Ω.
It was hard to find any 260Ω potentiometer on the internet. The one I did find was a 100 watt (way overkill) 250Ω unit on
Amazon
.
It can be tried right at the transmitter's removed Cannon plug.