I guess best thing is to check the gauge and wiring first.
Back by the fuel tank there will be 4 wires that go to the top of the tank.
1 pair is fuel pump's 12volt and ground
1 pair is fuel level sender's pulse 5volt and ground
Pink/black stripe wire and Black wire are fuel pump's 12v and ground respectively
Yellow/white stripe wire is from fuel gauge, unfortunately you can not test this wire with a volt meter.
Orange wire is the Ground for sender.
Ford fuel gauges(1989 and up) use 16ohms = empty and 158ohms = full
0 ohms = short to ground
1,000,000,000 ohms = broken connection
So if you disconnect the wires and turn on the key you should see fuel gauge go up to, and passed, Full, high ohms
If you Ground the Yellow/white wire(key on) the gauge should go to Empty
Also test the Orange ground wire, if it was loose I would expect Full on gauge not empty but.......never hurts to check a ground
If gauge doesn't do either, then problem is in the dash, most likely Anti-slosh module.
Google: Ranger anti-slosh module
lots of info out there on replacing or by passing it
If gauge behaves correctly then you will need to replace sending unit in the tank