The fuel pump relay center is 12.00 voltage at fuel pump conection at gas tank is zero (nothing) even when hot wired

I just looked at a wiring diagram of the fuel controls for this model: there is no fuel shut-off switch in the wiring. It's pretty straight forward, typical fuel pump controls: the fuel pump relay is in the under-hood power distribution center. When this relay is turned on, power is sent to the fuel pump, nothing else is in the path of the hot wire to the pump module so it (the pump) should be working.

So if pump is not on, you can diagnose the wiring right here at the fuel pump relay. First you verify the power feed for the pump is available at the relay. (One terminal at the relay will have battery voltage with key off. If you pull the relay out and use a test light, one terminal position will be hot.) Next you verify the relay is working, sending power to the fuel pump in the gas tank. You do this by having someone cycle the key to on, while you hold a finger on the relay (it's back in place) to feel it click on. You should feel it, maybe even hear it, the relay will energize every time the key is turned to on, and this is what sends power to the fuel pump.` If it all works, and the pump is not on, the pump probably needs replacing. If the pump relay is not clicking on, that's a wiring hassle, including the wire to the engine computer. The pcm is what controls the relay turning on.
Do you know if the fuel pump has ever been replaced in the car? If it is original, it has been a good long run.

You said you jumped the wires for the pump? Was that at the pump relay?
If you have a voltmeter or test light, keep the jumper wire in place and check for voltage at the fuel tank connector. The pump wire will be gray. With relay out and jumpered there, you should have battery voltage at the fuel tank connector. The key doesn't even have to be on, cause the relay has voltage to it at all times. If you jumpered it right (terminals 87 and 30 on the relay), and no voltage at the tank connector, you have a broken fuel wire somewhere between the relay and the fuel tank.
If you do have voltage at the tank, but the pump still won't work, only two possibilities, a bad pump or the ground for the pump is lost. Check the pump ground first.

Try lowering the tank enough to get the filler hose off, then you can get a siphon hose into the filler opening.

Or, you could open the fuel line at the filter, then jumper the fuel pump relay terminals. Pump will turn on and push gas out the line. Careful to get your jumper wire into the right terminals. You can damage the computer if you put voltage into the wrong terminal. The relay will have one hot at all times terminal- find that with a test light. Then you will jump the hot terminal to the terminal that has the fuel pump wire going to the gas tank. The relay should have terminal descriptions on it. The jumper wire goes with the two power side terminals, not with the coil side of relay. Post back if that's not clear.

Well you use a fuel pressure gauge to check pressure at the injector rail, and you can check for power and ground at the gas tank to make sure the pump is running.

the fuel pump working good and the relay too , i change the egr valve and another valve go in the air filter and nothing . now when i put the swicth the pump start runiing and them stop them start runing alot of time . now i check in the fuel injector if i got gas them i push the little thing in the injector them push a lot of gas .... now today i go put down the gas tank i go make sure if not have a electrical problem in the fuel pump. i hope this is the problem .....

http://www.bbbind.com/free_tsb.html free wiring diagrams ! Enter vehicle info. year , make , model an engine size . Under system click on engine ,then under subsystem click on fuel controls . Then click the search button , then click blue link .The 7th diagram down shows two fuel pump relays , This I have not seen before ! One is speed cont. relay an the other is just fuel pump relay ? The speed control one has a resistor in the electrical circuit . That is way your droping voltage .
Fuel Pump Electrical Circuit Diagnosis (VIN K)
Fuel Pump Electrical Circuit Diagnosis (VIN 1)

The PCM alters fuel pump speed by energizing the fuel pump speed control relay. Under normal conditions, the fuel pump speed control relay is energized. The applied voltage to the fuel pump is controlled by a resistor assembly. When higher fuel volume is required due to increased engine load, MAP sensor value over 90 kPa the PCM de-energizes the fuel pump speed control relay circuit. The increased voltage to the in-tank fuel pump allows a higher volume of fuel to be delivered to the fuel rail. The PCM also compensates for low system voltage by energizing the fuel pump speed control relay.

Have it check for codes !
Did DTC P0230 or DTC 1260 set?
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Go to DTC P0230 Fuel Pump Relay Control Circuit or DTC P1260 Fuel Pump Speed Relay Control Circuit
Go to Step 3

Gauge is not connected to any relay,its a signal from the fuel pump sending unit, you do not get voltage from that wire for the sensor you need to use a multimeter and test for ohms, every manufature is different and cant recall what it should be empty or full.

Get a shop manual or even call the local repair shop/dealer and they might give you the information you are looking for, but sounds like you have a bad sending unit and need to replace it as an Assembly.

More likely the fuel pump.........check for power to the pump on the gray wire at the fuel pump connector at the tank.(wires from the tank)You should see a prime cycle voltage as you turn the key on...if the key has been off 15 seconds. If you see a test light, light.......change the fuel pump.
Tip....a lot of relays are the same in the relay center....switch the fuel pump relay for one of the (same) others to test it if needed.

Before you do this....sit in the car and turn on the key to run.....not start.......do you hear the pump do it's prime cycle?
Total silence means.......in 99% of cases...a new fuel pump is needed.
If you hear it.......no pump should be needed....look elsewhere first.

Dear cdkkks,

Replacing a fuel pump in modern cars requires some preliminary electrical, fuel test analysis work. I have noted some professionals indicating you need to run car until gas lines, tank is empty; more than likely, if your fuel pump is defective, you cannot start the car, car is unoperative; you will attempt to start car, starter will turn the engine over rapidly without starting, let's assume you are in this condition.

First we need to test the fuses and fuel pump relay, basically the electrical opportunities on your vehicle, the relay panel is on the fender well, driver side, lift the relay control assembly from the fuse center and press the tab on the end, push down and this will release relays from the cover. This relay control panel includes the PCM power relay (left side in original position) Fuel pump relay (Center) this is the relay you are concerned with and the Air Conditioning relay on (Right). If you have friends, or associates who have electrical equipment to test the fuel pump relay, utilize their help, some automotive shops will provide this service. Checking the relay circuit with a jumper wire, any scrap piece of wire, 16-18 gauge will do; as you are looking directly down at the relay opening, you will note an opening at the 6:00 and 12:00 clock positions, 6:00 is the positive, 12:00 is the neutral, volt meter set for volts will confirm. Open the gas cap from the fuel tank filler pipe, insert the jumper wire and carefully listen for a whirring sound. If there is no sound and you have confirm electrical pump fuses, fuel pump relay is working properly (Voltage is pressure, battery voltage and slightly less voltage at the relay circuit when ignition key is turned on) then we have couple more checks to perform before we replace fuel pump. Let's check the fuel rail pressure on your Ford Crown Vic, obtain a fuel compression gauge with a Ford Schrader valve adapter, check to verify that no fuel pressure exists. If "NO" fuel pressure exists, and we have confirmed the voltage integrity of relay/fuel pump circuit, then we are ready to remove fuel pump. Use a simple gas siphoning kits from your local auto parts outlets to safely remove all remaining gas from gas tank, use appropriate gas tanks to store fuel; safety is the key here, gas and gas fumes are extremely dangerous; use appropriate chemical/gas gloves when siphoning/handling gas.

(A) Park your Crown Vic, perferably in a garage, concrete floor and make sure there is enough room around the back of the vehicle for you to work and move tools around.

(B) Raise the back of your car using a floor jack and support it safely on wheel/jack stands; remember, the driver side rear wheel must be removed in order to remove the fuel tank filler pipe, place your wheel stand (supplement with 2 by material for proper height on frame,slightly forward of rear wheel); safety is the key issue here and I cannot overly emphasize this issue, heavy wheel stands should be supporting the right rear wheel and frame, slightly forward of rear wheel, driver side).

(C) Disconnect the fuel tank filler pipe and the fuel pump connector located above the cross member underneath the vehicle, you must remove the (3) screws on the topside (fuel tank fiiler pipe) and approximately (4) screws on the bottom side, and the (1) screw adapter plate where the fuel tank filler pipe is inserted into the gas tank, top of wheel opening, underneath the vehicle. After these connections are removed, push the fuel tank filler pipe further into the fuel tank, allowing you additional room to lower the filler pipe from it's current position, downward; once you have sufficient clearance, twist, turn left, slightly back and forth movements and carefully pull outward, removing the filler pipe from gas tank. Do not damage the rubber groment in gas tank as you remove the filler pipe. As a note, when you reinstall the filler pipe, insert small amount of vasoline on filler pipe end that is inserted into the gas tank to facilitate the installation process.

(D) Support the fuel tank with a jack and remove the nuts from the holding strap using a wrench or ratchet and socket. Move the strap away and slightly lower the fuel tank in order to disconnect the vapor tube from the tee connector on the right and the vapor line from the canister tube. Discard the fuel tank mounting studs and replace with new fuel tank mounting studs on the reinstallation process.

(E) Unplug the pressure transducer electrical connector located on the top rear corner of the fuel tank.

(F) Clean area around the mounting fuel pump mounting flange. Remove/disconnect the fuel lines attached to fuel pump mounting flange then remove the fuel pump mounting flange mounting bolts in a crisscross pattern.

(G) Lift the fuel pump assembly off the tank. Replace the new fuel pump in the assembly and install the assembly in the tank. Install the flange screws and torque to approximately 89 inch lbs using a crisscross pattern. If no torque wrench is available, tighten to a snug fit and stop.

(H) Afterwards, raise the fuel tank enough to attach fuel lines and vapor lines indicated above, item D. After connecting all lines, raise tank with floor jack to its original position "carefully" and utilize the new mounting bolts, securing straps in their original position and torque bolts to approximatlely 25-30 lbs torque.

(I) Install the fuel tank filler pipe per the aforementiond process reversed.

(J) Review your connections and then carefully lower the vehicle, use a gas container, input 4-5 gallows of gas and start the engine and check for leaks.

Wishing you the very best,

drprice

I would start by checking you switch for the tanks to make sure it is working right and if the front tanks fuel pump does not work after you check the switch I would get a 12 volt electrical test light and see if your getting power to the front fuel pump if your getting power to it I would say you have a bad pump . But some times the pump will run but the diaphragm gets weak in them.