Troubleshooting your fuel level sender

[RICE RACING]

good thread, should be more like this!

[Sinfidelity]

Damn it's weird!

So I cut out the fuel sender plugs n cable from an old loom to use as a test cable enabling me to read my running car and test in parallel, solo and in series to try figure this out.

All seemed to be good till I hit half tank while testing both senders parallel
Full 7-9ohm
3/4 55ohm
1/2 94 ohm
1/2 142 ohm left side only

Not sure what to follow here seeing as the right side isn't gonna change now till empty.

[JL1RX7]

Now since it is a averaging sensor I wonder if it only takes input from certain OHM readings. So say anything above 90 OHM it only reads from one side vs the other.

Most of the sensor's I use are for temperature across a large area. Not a split sensor system like this. But trying to see the logic of what they are trying to read, then using a sensor to read it. I could see it doing something like that.

[Sinfidelity]

Originally Posted by JL1RX7

Now since it is a averaging sensor I wonder if it only takes input from certain OHM readings. So say anything above 90 OHM it only reads from one side vs the other.

Most of the sensor's I use are for temperature across a large area. Not a split sensor system like this. But trying to see the logic of what they are trying to read, then using a sensor to read it. I could see it doing something like that.

I think I figured it.
The gauge cuts the circuit to the right sender once it gets below half. Much like how it activates the fuel light at near empty.
Then only reads level from the left.

My final readings were this

Full 7-9 together
3/4 55 together
1/2 142 left side only
1/4 200 left only
E 326 left only

I'm still not convinced it's 100% accurate but I think it's close enough to program a new single sender