I found this thing in my glovebox and have no clue what it is and was hoping someone in the community has seen it before. Also I found something called an anti-slosh device in the glovebox which is the circuitboard. Would that not being installed cause the gas gauge to not work at all? It shows full 100% of the time? I've already bought a new fuel pump, housing and sending unit assembly.

 

IAC Valve, located on engine intake near throttle, computer uses it to set idle RPMs

And Slosh module, or anti-slosh module to be more precise, its located on the back of the instrument cluster, it prevents gas gauge needle from going up and down when ever you go around a corner and the float in the gas tank goes up and down as the fuel "sloshes" around in the tank
Common failure on Fords, causes gauge to show empty or full all the time

These could be spares picked up at wrecking yards or parts were replaced and these were given back to previous owner as proof parts were changed
Only way to test them is to install them and see if they work

 

1st item is an IntakeAirControl\IAC Valve (or IdleAutoControl\IAC Valve as I prefer to call it),
mounts on the engine IntakeManifold throat (under the plastic vanity cover).
Click here for more info on the IACValve.

2nd item looks like (?) the FuelGuage circuit board,
mounts on the backside of the InstrumentCluster into a FlexCircuitBoard socket.
Click here for more info on the InstrumentCluster.