Crown vic 2000 wont crank ? battery, alternator,starter,starter relay all good ?

State of battery, battery cables, ignition switch and its wiring, starter and its connection, neutral safety switch and related fuses and relays .

Is the red light in the center of the dash , on top of dash panel not instrument cluster flashing when trying to crank the engine over ? If yes you have a anti theft system problem ! If the light is not flashing you can check for power an ground an PCM control at the starter relay in the under hood battery junction box ! Bottom of relay or side show pin numbers ! Pin's 30 & 86 should have battery voltage ! Pin 87 - ground through the starter , Pin 85 should have nothing unless cranking engine over . The PCM supply's a ground here energizing the starter relay ! You can also test this by using a test light . The clamp end to battery positive , the point end touch to pin 85 relay socket while cranking ! Test light should light !

Dead Battery
Bad Starter Solenoid
Bad Starter

The starter solenoid clicks, your past the
security system & starter relay

Are you saying it won't crank, or won't start ?
If it does not crank, and you have replaced the battery and starter, the problem may be in the neutral safety switch.

If it doesn't turn over it may be your starter going. or a weak battery. start with that first, insufficient fuel pressure won't prevent you car from cranking, but weak battery or bad starter will. If you can jump it and it starts its probably the battery if it doesn't crank then its probably the starter. Good luck

buy a cheap volt meter check voltage on both sides of the starter seleniod on the fenderwell if you have 12 volts on both sides while cranking test voltage at starter if you have 12 volts at starter with fully charged battery and it doesnt start you will need a starter it also sounds like you might need an alternator once you can get it started

ignition switch or starter relay or a wiring problem

i have a 1999 Ford Crown Victoria Police Interceptor. you have a short in your wiring harness leading to your battery. this happens every time with these cars, good battery-good starter-good alternator but car still wont turn over because the power from the battery isnt able go directly to the motor. check your relay circuits and harness.

Check the starter solenoid. Usually mounted on a fender well. Find by following the + battery cable.

did you check the inertia switch?? that's what happened to mine