Picture of the location of the fuel pump relay for a 1999 ford ranger

Before you begin, it is important to note that modifying electrical systems in a vehicle can be dangerous, and it is always best to consult with a professional mechanic or electrician before attempting any repairs.
That being said, here are the general steps for wiring a replacement fuel pump into a 1999 Ford Ranger that has a wire for a flexfuel sensor on the truck harness, but not on the replacement fuel pump:

1. Locate the fuel pump relay in the power distribution box under the hood of your Ford Ranger. The fuel pump relay is usually marked on the cover of the box.
2. Remove the fuel pump relay and identify the two pins that connect to the fuel pump.
3. Connect a wire to each of these two pins on the fuel pump relay.
4. Connect the other end of these two wires to the corresponding wires on the replacement fuel pump. Typically, one wire will be for the power supply, and the other will be for the ground connection.
5. Locate the wire for the flexfuel sensor on the truck harness. This wire will be a different color than the wires for the fuel pump.
6. Cut the wire for the flexfuel sensor, leaving enough room to splice in a new wire.
7. Strip the insulation from the ends of the cut wire and the new wire that you will use to connect the fuel pump.
8. Twist the bare ends of the two wires together and secure them with a wire connector or solder.
9. Connect the other end of the new wire to the appropriate terminal on the fuel pump.
10. Test the fuel pump to make sure it is functioning properly before starting the engine.

It is important to note that the exact process for wiring a replacement fuel pump can vary depending on the make and model of the vehicle, as well as the specific replacement part being installed. Therefore, it is always best to consult the manufacturer's instructions and wiring diagrams, or seek the advice of a professional mechanic, before attempting any repairs.

Fuel shut off switch may need to be reset. A friend of mine had it trip when he had a flat tire some years ago on ford car. The reset on his was behind the plastic piece to the right of where the video below. Video below shows fuel shut off/inertia switch on upper floorboard passenger side.
Inertia Switch Explained Removed and Replaced 98-12 Ford Ranger - YouTube
2002 Ford Ranger Fuel Cutoff Switch - YouTube
You can try swapping out your fuel pump relay to make sure the relay is not bad. Below link may help
1999 Ford Ranger Fuel Pump Relay, Fuel Pump Fuse & Starter Fuse Location - YouTube

Have you tried changing the fuel pump relay, or fuse? I have always went by one rule first and that is (never overlook the obvious) most of the time it's something simple hope this helps

Click on link to see fuel pump relay's location.http://www.rangerpowersports.com/forum/f329/2001-ford-ranger-fuel-pump-relay-location-199081.html

It's on the right front fender relay block, furthest to the rear.

The reset button is on the passenger side floor at the corner where the dash meets the door.You'll need to pull down the corner of the carpet to see it.

Check the inertia switch (refer to owners manual for it's location). Also check the fuel pump relay.

Fuel Pump relay switch is in the main box usually located on the drivers side Fender in a black box. According to the owner's manual in the power distribution box in the engine
compartment (Ford recommends disconnecting your battery)
Relay # 5 is the fuel pump relay , and also in the PD BOX is a 20 amp mini-fuse
for the fuel pump relay + RAP module in location # 9


( P.S. - don't forget your fuel pump inertia switch , in the right front passenger area ,
by the right front kick panel )Sometimes this gets kicked by passenger or if the car is bummed hard it could set this item to shut down fuel system. Best of Luck

Hi..my name is Keith..and the 2 things that i know of...that will not let power go to the fuel pump is 1..the fuel pump relay being bad..or 2..that something has tripped the Inertia Switch...and it needs resetting..i hope this will help

There is a Fuel Pump relay. Not sure if Ford has a Relay Box under the Hood though. There are also Fuses that Control some items of the Fuel System. Try the Relays first and see what you have.