A low pressure alarm is a waste of time and money. Either a fuel pump works works or it doesn't.
Two indications that your fuel pump may be failing. Loud operation and intermittent operation. If you have a current clamp style amp meter check the current out of the fuel pump relay.
Depending on what model Ford vehicle you have and what model year, you may or may NOT have a "returnless" fuel system. The return fuel has an extra pipe going back to the tank from the fuel pressure regulator on the fuel rail. Returnless systems have an electronic controller (somewhere) that controls pressure.
Actron CP7838 Professional Fuel Pressure Tester