Question about Mercury Grand Marquis

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My 1999 mercury grand marquis anti theft light keeps blinking fast. i've tried taking my battery post off for 3hrs. still doesn't crank. Any suggestions?

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Posted on Jan 02, 2017

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SOURCE: 1993 Mercury Grand Marquis

starter cylinoid

Posted on Jul 07, 2008

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SOURCE: 1999 ford winstar anti theft problem

Fords have a chip in the keys and a reader in the ignitions switch, when you insert the key and the theft light stays on solid then the key has passed. If the light flashes quickly then the key didn't pass the check and the vechicle will not start. This can some times be a key problem and some times a reader problem . But the keys can only be programed with a computer in this situation. The dealer or most lock smiths have these computers.

Doc Jones Auto & 4x4

Posted on Mar 11, 2009

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SOURCE: anti theft dash light is blinking on my 1998 rodeo

I'm assuming its an original alarm or system that came from factory or dealer. When the light blinks is because the alarm is activated. Look underneath the radio the alarm brain might be there. There will be a label on it saying alarm or security system etc. Disconnect the harness to it and try operating your vehicle.

Posted on May 06, 2009

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SOURCE: 1999 mercury cougar. won't start...cranks...battery ok.

V6 ? 4CYL? Have you verified SPARK? Did anyone check the "fuel pump inertia switch?" Its in the right front kick panel. If it was a "Anti-theft Issue" the light would be on or flashing.

Posted on Nov 03, 2009

  • 92 Answers

SOURCE: 1998 ford expedition that won't start. it cranks,

The theft light blinking indicates a PATS (perimeter anti-theft concern.It means that the computer has not recieved a signal from your key when trying to start the vehicle. A few things could be wrong.
1...The key you are using to start the vehicle is not programmed to the vehicle or broken internally. So try a different key(one that you know is programmed to the vehicle) if you have more than 1. If the theft light goes on and flashes when you try to start the vehicle, you must wait about 5 minutes before trying the second key because the computer goes into antiscan or theft mode and wont let any keys start the vehicle.
2... There is a small transciever ring located arount the key cylinder which recieves the key signal. The wiring for the tranciever runs down the steering column into the dashboard wiring. Sometimes these wires break. If you have a tilt steering wheel, move it all the way down and try to start, then try moving it all the way up and try to start. Keep in mind the antiscan that I mentioned in #1. If this works then you need to check the wiring at the base of the steering column. A white connector with 4 wires. Pull on each wire to see if any are broken.
3... Check fuse #30 on interior fuse panel. If it is blown then you will have to trace down the cause of the short. The ignition coils are on this fuse also so one could be shorted. Disconnect all ignition coils(you may have 8 located on each plug if 5.4l engine or 2 located on l+r front of engine if 4.6l engine) and see if the short is gone. If the short is still present disconnect the radio noise supression capacitors( small black box approx 1" x 1" square with a single wire coming out) that are located on the left and right front of the engine. Pay close attention to all the wiring around the coils, look for any areas that may have rubbed thru and shorted.
These are things that I would look for first and are the most likely causes. This should get you started in the right direction. Be patient and post your findings if you fix it or not.
Good luck

Posted on Apr 10, 2010

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I have a 1998 mercury grand marquis that turns over but wont start the fuel pumpis working ive changed the crank sensor and I have been recently told it could be the immobilizer can you help?

Does the anti-theft light flash really fast when trying to start the vehicle ? Learning how to test the systems rather then going by i was recently told it could be this or that . I say your best bet , have it towed to a qualified repair shop . Because if it is the anti-theft system ,your not going to be able to do anything with it .

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After change battery car couldnt start and security light blinking continusly please help me

You will have to take to the dealer an have the PATS system reset , need factory scan tool to do it . PATS - passive anti-theft system .

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2003 grand marquis ign on no crank no spark fuel pump works

Sounds like anti theft is Tripped... but you could try
looking in the fuse box to see if there is an ignition fuse. Accessories should come on then gauges ( gas, warning lights) then fuel pump followed by some clicking as the relays pop to life and injector click... if you are not getting this then look at the dash and see if a key sign is lit or the word theft is remaining lit... if no lights and no power check the headlights and horn to rule out the battery... if that all works check the fuses in the dash...

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Factory installed anti theft & keyless entry system

If is the original key fob, you may need to reprogram it

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