Secruity alarm light blinking car want start on a 1999 mercury cougar

How to program a key for a 1999 Mercury Cougar?

1999 Mercury Cougar Keyless Entry Remote Fob Programming Instructions

1. Turn the ignition from OFF to RUN 4 times within 6 seconds.
2. Turn the ignition OFF. ...
3. Within 20 seconds, press any button on the first keyless remote. ...
4. Within 20 seconds, press any button on second keyless remote.
5. Turn the ignition to RUN.

1999 Mercury Cougar Keyless Entry Remote Fob ...

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Maybe but I believe you have a dirty or bad injector-
you need to pull the engine codes for the engine light to see what it says. Any auto parts place will do that for you for free.

There isn't one. The alarm is hot at all times. Direct battery power. You will need an electrical schematic to check for power to the security module.

your battery was too low to accept charge through the cables. Try taking it off and get it charged up.

instead of explaining it myself, here's a great resource, if it is indeed the alarm that is plaguing you...

click HERE!

You can disengage alarm with a remote if you have one otherwise, close bonnet, all doors and lock the car by turning key completely to the left and right few times and do the same to unlock. This will dead lock and unlock the car. When you hookup the battery make sure you connect red wire first and then the black one.

If it is a factory alarm go to your local Mercury dealer with your VIN and get keys from them.

Yes to either one. How about the Main fuse to the PCM or a fusible link

Fix the problem with the air bags.

Alarm imobiliser faulty ..