Negative Earth and MM/SII fuel guages

[turbominor]

Has any one converted and MM or early SII to negative earth as i am having a nightmare getting the fuel guage to work.

if i disconnect the wire to the tank the gauge goes to full? but earthing the wire to the tank the guage does not move...

It was ok before converting to neg earth

[forbesg]

Has any one converted and MM or early SII to negative earth as i am having a nightmare getting the fuel guage to work.

if i disconnect the wire to the tank the gauge goes to full? but earthing the wire to the tank the guage does not move...

It was ok before converting to neg earth

All I did was turn the battery around on my SII (`54).
Fuel gauge works fine. I guessing, but the gauge seems to work on the strength of the magnetic field rather than polarity.
Check the obvious, continuity of the sender wire and that the resistance of the sender changes from low to high.

Cheers Grant.