I have a 1996 Ford Mustang GT 4.6. My car would start then turn off as soon as the theft light starting flashing, I tried disconnecting the battery, turning the key in both the passenger and driver doors, and I split the wires and ground them in, no codes came up when they read it either. The theft light isn't coming on anymore but my car still won't start, any other suggestions? The car will start for 5-10 seconds then cut off again.

The fuel pump or ignition circuit is disabled by the anti-theft system. Beginning with some higher-end models in 1996, Ford embedded an RFID chip in the plastic on the key handle. If that is broken out or damaged, you're locked out, and you'll have to replace the key.

You say 'won't turn over'. Do you means the engine is not cranking (turning over), or do you mean it cranks but doesn't 'start'? Did you disconnect the battery when you installed the fuel pump.

The flashing anti-theft light may be a clue here.

1. Insert the key into the driver's side door lock.
2. Turn the key once, but not all the way to unlock the door. Leave the key in this position for 40-60 seconds. ...
3. Do this again, but turn the key in the opposite direction.
4. Remove the key from the door, get into your Ford, and start the engine. The system should be reset.

How to Reset the Anti-Theft System on Your Ford

Or there are videos. You should also check for DTCs, diagnostic trouble codes.

https://www.google.com/search?q=2004+ford+mustang+reset+security+system

..

The anti theft light is flashing because the key used to start the vehicle is not paired to the vehicle and has activated the immobiliser!

From my experience...
A non PATS coded key SHOULD not turn the STARTER...!

If ANTI-THEFT were invoked... you can attain a not start condition which the Owners Manual says must be cleared by the dealer.

A working PATS key should disable the anti theft... by turning the ignition on... ELSE try your other key.

The SecuriLock [PATS]
passive anti-theft system is not compatible with
non-Ford aftermarket remote start systems. Use of these systems may
result in vehicle starting problems and a loss of security protection.

Owners Guide (post-2002-fmt)
USA English (fus)

OWNERS MANUAL
Ford 2003 Mustang Owner Manual

SHOP MANUAL
Ford 2003 Mustang Workshop Manual

99 F-150 ignition/anti-theft question - Ford F150 Forum - FordF150.net

www.fordf150.net > ... > Electrical (Everything except audio systems)

Sep 16, 2009 - I had 2 keys for the truck, one worked perfectly fine, the other wouldunlock the ... over but the anti-theft light flashes and the engine won't actually start. ...Should I just spend the $80 for the switch and hope that is all it needs? ... for Fordkeys (Later 1998-newer Ford, Lincoln, Mercury) ... Mustang 1998 - 2001

electrical - Can I disable antitheft (PATS) on 03 Mustang ...

mechanics.stackexchange.com/questions/.../can-i-disable-antitheft-pats-o...

Jan 4, 2012 - So my question is: Is there a way to just disable the anti-theft system? ... This will make the car always 'see' a key with a chip. ... as they are usually intertwined with the anti-theft system to ensure the engine will not start. ... Where is the Wiper Relay/Control Module located on a 1994-1998 Ford Mustang??? 7.

How to Turn off Theft System on Cars: 7 Steps

www.wikihow.com > ... > Cars > Car Maintenance and Repair

wikiHowJump to Questions and Answers - Be the first to ask a question about this topic: ... Itwill not start and your battery will die. ... Reset a Check Engine Light ... Thanks to allauthors for creating a page that has been ... How to. Make Oat Flour. Cook Bacon in the Oven ... People are incredibly helpful and open to new ideas ...

since the radio is resetting, i would first check the battery terminals. the radio has to power inputs, so if its resetting then your losing both at the same time. one wire more or less comes directly from battery, its the memory wire to get a presets and times.

When the car is off, a slowly flashing anti-theft light is normal. When the key is in one of the on positions, that light should go off. If it thinks it detects a theft condition, the light will flash quite rapidly and prevent starting. You can also check the mileage readings in the odometer display. If you see dashes instead of numbers, that is a clue that some part of the onboard computer has gone wacky.

You already tried one of the steps that I would recommend (unlocking the door, though that may not be enough by itself. Here are a couple of things to try.

First, pray that this isn't the anti-theft computer gone awry. That is uber expensive to replace. Following that prayer ...

Verify that the battery is fully charged and showing about 12.8 volts with the headlights off and about 12 volts with headlights on. If the voltages are low, try jumping the battery to see if you can get it to start. (A low battery can occasionally cause an anit-theft fault.)

If you have another key, try that one. The chip in the first key may have gone bad. If that doesn't work ...

Disconnect the battery negative cable for 5 minutes. Reconnect, and lock and unlock the doors several times with the remote. Check to see if the anti-theft light is still flashing rapidly. If not, try starting.

Anything more than these steps will need to be handled by a qualified shop. (For example, a wire in the steering column could be damaged by the tilt mechanism, or the computer malfunctioning).

Good luck.

sounds like your battery is getting to cold id try insulating the battery . if not possable just take out and keep warm, like mabey room temp..

Undo the battery for 10 minutes, plug it back up, let the car sit for 20 minutes WITHOUT trying to start it, then try to start it. it should work.

Blown Head Gasket --white smoke is coolant