Car Alarms: 2000 Sable car alarm, keyless entry system, bad habit

Question
Our 2000 Sable has the bad habit of setting off its alarm (horn, lights, etc.) at the most inopportune times.  Dealer can not isolate the problem - deny that the problem could exist.  We are tired of getting up in middle of night to disable, but need to have the car locked.  Any suggestions?  We believe this to be a factory installed alarm - also the 'theft' light is blinking super fast on the dashboard - have been unable to disarm anti-theft with instructions in manual.  

Answer
The 'theft' light in your dash is an indicator for the securilock system and although it is part of the entire anti-theft package of the vehicle it is not typically an indicator of the theft content alarm, which is what sounds the horn.  If your security system is indeed going off for no apparent reason I would have to think that one of your door pins is going bad.  There are a couple of options that you may want to try.  Your factory alarm will arm in one of two ways, the first is by pressing lock on the factory remote.  The second is by pressing lock on the door with a door open.  Your factory alarm will not arm however if the lock is pressed with the door shut.  If the dealer can not find a problem, I would suggest taking the car to a local stereo shop and inquire about an aftermarket keyless entry system.  The aftermarket keyless will be able to disarm the factory alarm on unlock but it can also allow you to lock your doors via the new remote after the door has been shut, thus preventing the factory alarm from arming in the first place.

To the problem with the theft light flashing...inserting your key into the ignition cylinder and turning it to the run position should cause the light to stop flashing and go out to verify the securilock system is reading the proper key.  If this does not go out you will not be able to start the vehicle at all.

Now with all of that being said, it is possible that your vehicle has a code-alarm manufactured Ford security system that was dealer installed.  It has been my experience that these systems go bad over time due to poor installations performed by under qualified technicians.  If you take down the dash panel(s) under your steering column you would see an extra 'box' with several harnesses running to it, it will look like it was added and not installed by Ford.  Simply unplugging the harnesses from the brain would stop the alarm from sounding but will also stop your keyless entry from working so you would be back to my original suggestion of having a new keyless unit installed (heck even a remote starter could be added if you want).