Replaced the battery.in my 1996 taurus, and now theft red light blinks and car wont start, ran perfect before this.. help me!!

Try leaving the key in on for 10-15 minutes. If the blinking theft light stops blinking and goes out, it has reset. Turn key to off, and then try to start it.

Try pulling the fuse for the anti theft system and starting. If the car starts normally, then the problem is with the theft system. The theft system will reset itself after a period of time.

get your battery checked

yes the fast blinking theft light indicates that theft mode is activated. you wont be able to start the vehicle until you have the keys reprogrammed at your local ford dealer.

your anti theft is more than likely doing it is their a key pad where you enter a code? If so you need to enter the code that was hard wired to it when you have a bad battery or change the battery the system defalts to the hard wired code, if you don't know the code it should be on a sticker in the trunk I think it is on the hindge to the trunk lid right side!

go to autozone they can reset code with their code reader.......try to disconnect battery for 5 minutes the reconnect. this will clear some of the computer codes

Either you may be using a key that you had copied from the original or your chip went bad in your original key. Most of cars now a days have the key censor in the key so if it is the incorrect key it will not start your car or if it does not read that chip it will not start

make sure battery is fully charged and have tested for a weak cell and check out the alternator and the drive belt and if the car has over 40,000miles it needs a tune up plugs wires fuel filter and if all this fails have the timing checked and don't forget the crank sensor to have it checked

The taurus is equipped with what is called a PATS (passive anti theft) that wont let the car start until it recognizes the key in the ignition, some things to check, first when you put the key in and turn the car to run (not start) does the theft light blink fast in the dash or is there a red on light on the dash that starts blinking? if so it is a PATS problem, the only ones I know of that can program keys are dealers, if the car wont turn over it probably is not a fuel pressure issue, the most common thing would be the PATS keys either unprogrammed or somthing wrong with the module. hope this helps

Mike. Please be sure the battery is good. and full charged.
OR if you have an other one, change.