Posted by Gordon on Wednesday, February 18, 2004 at 4:05AM :
In Reply to: Re: 3 Stud fuel gauge vs. one Wire Fuel sender? posted by Dave on Tuesday, February 17, 2004 at 6:11PM :
I have this too.
As I understand it, one terminal on the gauge takes power from the ignition, and the other two each run through their own wire to the sender unit, which has two terminals on it.
There are two complete circults through this guage and sender, and the position of the sender float alteres the balance between the current / voltage / whatever in each circuit, and the gauge shows the difference in the readings as the fuel level. Since it is two balanced circuits, there is no reason why it shouldn't work in the same proportions on 12v too, though I would be inclined to fit a dropper resistor on the line from the ignition to the gauge supply.
If it was all up and working properly it would be a much better system than the simpler, later system where power just runs to earth through one wire to the sender, as we all know those guages wave all over the place when you are moving.
Gordon
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