Fuel Cell and Digital Dash Level

[4000GT]

So I have an RCI fuel cell (which doesnt currently have a level sender), I want to add a level sender to the fuel cell (assuming thats possible), and use the stock fuel gauge.

So question is.... the ohm range on the stock digital gauge, I heard 3-120 ohms, and the RCI sender seems to be 0-90 ohms... advice? Its in a race car so doesnt have to be exact, but close enough and consistent.

[Ivan141]

I should be able to think up something for converting that signal (having a degree in electrical engineering), but I'm drawing a blank at the moment.
Would probably need to be an active circuit.

You could just put a 30ohm resistor in line and mark off the point where the needle sits where the actual fuel sender is at 0 ohms.

[4000GT]

Yeah I have friends that can make a circuit board if needed, but the easiest route is to get one that fits first!

[4000GT]

Ok so that didnt work with the resister...

On further reading some people say the fuel level is voltage driven, 0.1v for empty and 4.9v for full, can anyone confirm what it is???

[Ivan141]

If it is voltage driven then you could just use the new sender without problems. In that case I'd expect you need to supply a 5v voltage and the cluster 'reads' the voltage coming out of the sender.