Either your starter solenoid, if not check the neutral safety or clutch safety switch.
most likely tha starter is bad or the power to the starter is bad
Then why did you replace a perfectly good starter? ALWAYS test old parts and know what you're doing BEFORE you start throwing new parts at a problem. Find out WHY it isn't starting. Does the starter engage and turn the engine? IF it does, then the starter is probably fine. If not, check the starter, battery, electrical connections, ignition switch and neutral safety switch. If the starter has ALWAYS engaged and turned the engine, you should not have changed the starter in the first place; instead, you should be finding out what's wrong.
changed seliniod on starter and on firewall ,checked fuses still won't turn over, if I cross the upper seliniod with a screw driver it turns over but won't start?
I'd check two things: I don't remember what year Ford changed over, but if yours still has the starter solenoid on the fender, make sure you haven't crossed the small wires. If the solenoid is on the starter, are you certain that you've wired the starter right? There are a couple small wires that connect to the starter,if you connect them wrong it could the cause problems you describe. If you're CERTAIN that the starter and/or solenoid are connected properly, start looking seriously at the ignition switch.
it might of not been your starter to begin with. maybe a bad fuel pump
The problem may be with your starter and not with the clutch.
Check your alternator and your connections form the battery to the Starter. You may just have a bad connection If that does not work, your solenoid on your starter has gone bad, a new solenoid or starter may be needed. Check the start switch on the clutch pedal if so equiped.
Check spark plug wires, and voltage on the distrubutor.
factory security system. bad key, bad ign lock cylinder, switch etc. Get a test light, and check if you have voltage to the starter in the "start position". the runner is bad
If you can hear your starter motor turning but not the engine you have some teeth missing on the ring gear. If you can hear nothing, not even the starter motor solenoid clicking into place, you have a connection problem between ignition switch and starter motor.
You cant really, sometimes shadetree mechanics can get a few extra weeks out of a starter that has a bad solenoid by hitting the starter with something. After a while that wont work either. You can use a screwdriver to cross connect the two large terminals on the starter to bypass the solenoid but its not good to do and also dangerous. If you have some kind of ignition problem that you cannot figure out but still need to operate the car in emergencies or to keep from losing a job you can buy a remote starter switch from an auto parts store ( about $10 ) and connect the alligator clips to the 2 large terminals on the starter, then with the ignition switch in the run position press the button to start. Tuck the switch away under the hood for the next start.
Have you tested the starter itself? Remove it, take to Auto Zone/Advanced/etc. and they'll do a free bench test for you.
You should check the wires that are in the steering column to the ignition lock cylinder. They tend to break easily.
Check your electrical connections
it may be the starter going out doing it . it will kill the alternator if it keeps going . I know i had it happen to my 96 olds replaced the alt still didnt start and the starter fixed it
Check the 96 Caddys starter solenoid. Also check the wiring between the battery and the solenoid for any breaks or loose connections.
most likely tha starter is bad or the power to the starter is bad