Gas Gauge/Sending Unit problem

My methodology was to drain the tank with a syphon hose.

I had 20 1 gallon former windshield washer fluid bottles.

I measured the resistance at the sender (it would be a little bit higher at the gauge for the length of the wire, but to compare the senders it is ok)

I added 1 gallon at a time and bounced the car to allow the sender to move a bit. Waited for it to settle then read the resistance.

The Spectra and A100 both did the same thing with reading empty with 1/4 to 1/2 A tank left.

The later model OEM Mopar looks like the Spectra but the curve is more correct. It has the short arm like the Spectra which might explain the longer reading empty or full at the top and bottom of the scale.


I forgot to mention the gauges have a E and F adjustment in them. They have to be removed from the cluster to adjust it