I have had problems with this fule gauge and has never worked for me at all. I have put a new pump in and sending unit and still didn’t work, so I though that pump may be bad and Bought a new one and did that same thing. So I turned my key on and moved the float and when it’s at is top it read about 3/4 and won’t really go down past 1/4. But when it’s in my tank it seams to read a different reading sometimes.

 

Welcome to the forum

What is the YEAR of the Ranger?

And regular cab or extended cab?
They have different size gas tanks

You will need an OHM Meter to test the signal
1983 thru 1988 used a different gauge and sender than 1989 thru 2011
So the year matters

 

1992, 2.3, 2-4, single cab xlt

 

In a 1992 it may be an issue with anti-slosh module on the back side of instrument cluster

Usually if this goes bad tank will show FULL or EMPTY all the time, Google: Ford Ranger anti-slosh module
Read/watch some of the info about the symptoms, to see if may be the issue


All vehicles have some version of an "anti-slosh" module
As you drive and go around corners, or stop and go, the gas in the tank will "slosh" around, so the Float will go up and down, so without this type of module the gauge needle would be all over the place, which is not good for the gauge either
So this is a "delay" and "average" circuit, prevents instant changes on the gauge and averages out the OHM reading coming from the sender/float in the tank

There is a Yellow/white striped wire that runs from the tank to the cluster, this has the OHM reading the gauge uses
In 1992
16 ohms = EMPTY
158 ohms = FULL

You can use an OHM meter after unplugging its connector from the cluster to see if its in this range and steady, then rock the truck to slosh the gas around and make sure the OHMs go up and down as float goes up and down by doesn't drop out or jump up above 158 ohms