Car Alarms: car alarm or other problem, tow truck driver, pontiac grand am

Question
I have a 99 Pontiac Grand Am with a Pursuit alarm system installed.  

A couple of days ago I had to replace the battery in my car.  I drove it around the rest of the day and it worked fine.  The next day I went to go somewhere and the car would not start.  I called AAA thinking it was the alternator but when the tow truck driver came out he was able to turn on the car.  At first the car wouldn't start for him but the alarm went off.  He turned off the alarm and the car turned on just fine.  I drove it around a little but when I got home and turned the car off, the door locks wouldn't work and the car wouldn't start again.  

Since then the car only turns on sporadically but once it's on it runs fine.  In your experience is this a problem with the car alarm or is it a problem elsewhere in the car?

Answer
I'm guessing this is a power issue with the car's
alternator. The alarm sound
like it's responding to the power on/off fine,
but not starting correctly points to the charging system.

Take it into a mechanic soon to have it inspected.

Good luck with it.

ALARMTEK