G3X Resistive Fuel Sensor setup

Per the manual I wired my stock RV resistive fuel sensors on my GAE 24 as P244 pins 6 & 9 shielded.

There is a perceivable ramp .8v-2.1v (empty-full), but it's very small and very noisy especially < 7g it's just bouncing around virtually unreadable.

Should this be pulled up or conditioned?

Thanks,

-Bruce

Bruce,

Typically the resistive floats work well until the float hits the top of its travel. Because of the dihedral in the wing, the float in the wing root cannot measure the whole range of the tank. It is recommended to stop the calibration once the sensor value stops changing. If not, you will end up the top several gallons of fuel all having the same sensor reading. This will cause the gauges to move around a lot. I typically see the sensor rail out somewhere around 14-16 gallons on an RV-6 tank. I think the -4 would be somewhat similar. If you are having issues with the value moving around within the 0-14 gallon range, it could be that you have a bad sensor or a wiring issue such as a bad ground.

Thanks,
Levi

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So can i run a sensor in the tip and root of tank? Would i wire them in parallel or series?

Short answer; maybe... but don't.

So let's start with the maybe...

Because my fuel quantity senders are internally grounded, I could only do parallel, not serial as they both share a common ground I can't easily get that connection as it's in the sender.

But that said, it's still parallel and total resistance in parallel is...

1/Rt = 1/R1 + 1/R2

Which means you'll still see a difference if either change, so this isn't a totally wacky idea. That said... I think in practice with the way the float bobs around, you're going to get twice the noise and it's going to be an even awfuller signal (it's already pretty bad). So, I'd stick with the stock design.

Fuel quantity only has to be accurate at empty!

Thanks

Thanks for the feedback. Every good idea needs to be based on reality. Yes running two in parrellel really makes the signal a low value. I?ll keep this idea in the back of my mind and if I ever find a way to run them in series, maybe with a different sender, it will be resurrected..