Fuel tank sending unit resistance numbers

[Purple73Cuda]

What is the resistance numbers for the full and empty positions? It is for a 73 'Cuda.
I measured the original I have for the car. The numbers were Full 30.5 and Empty 87.1. I just want to see if I am close to where it should be. The gauge worked fine before I took the tank out.

[MEK-Dangerfield]

According to a manual I have, the range is 12 ohms to 70 ohms.

[Purple73Cuda]

So my sending unit seems to be close. Maybe the connections need to be cleaned to knock the resistance down.

[UKcuda]

It's the "full" end reading you need to look at most closely, the gauge is less sensitive to the lower end.  I believe this is why the rheostats in the senders are made with the resistance wires further apart at the higher end.

I've been playing with gauges a lot recently (it's sad I know) and I've found the internal resistance of the E-body gauges is only between about 12 and 17 ohms.  As the resistance of the sender approaches that of the gauge the gauge becomes very sensitive to it.  A difference of a few ohms at the "full" end of the sender will make a big difference on the gauge.

The senders all seem to be designed to drop close to 10 ohms for full scale, which means they actually overtake (undertake ?) the gauges in terms of resistance.

Don't know if that helps but there it is.

[JayBee]

Recently I did some sending unit work and here's my outcome:

At FULL my meter reads 9.5/10 ohms and the gauge needle goes just a bit beyond the full mark, so 12ohms should probably put it right on the full line.

At EMPTY my meter reads 70ohms. I ran the car to the empty line on the gauge today (had my son follow me to the gas station in case it ran out of fuel) and the car took 16.1 US gallons.
I don't know how low the pickup tube is sitting in the tank but I'd rather show empty and still have about 2 gallons in it.