1990 Ford Ranger think fuel pump stopped working

First thing to do would be to check the fuel pressure, then remember this vehicle has 2 fuel pumps, one on the frame and one in the tank.

Fuel pressure should be 40 psi with key on and engine off. If you have low fuel pressure then most likely the fuel pump on the frame rail is bad and will need replaced. This is also reffered to as the high pressure pump. If you have no fuel pressure but do have power to the pump in the tank, then you will need to replace at a minimum the fuel pump in the tank.

If you have no power and or ground to either fuel pump, then you will need to trace back the wiring and repair as needed.