2000 Explorer, factory alarm?

I'm trying to figure out if I have a factory alarm system installed on my vehicle. It's a 2000 Explorer XLT, I have the Theft light on the dash, keypad on the door, and a remote fob to lock/unlock the doors. When I push the lock button on the fob, once locks the doors, twice the horn beeps. I have tried to set the alarm off by pushing the fob twice, waiting a few minutes, and then reaching through the window, and opening the door. No alarm goes off. So I am wondering if there is an alarm installed? Thanks, Ted

The theft light on the dash should be a good indication. I've worked on many cars with factory alarms yet I never seem to know how to trigger them. I've tried what you did but that seems to disarm the alarm. I have triggered them before but it was always random, especially during remote starting.

On the Ford's, roll the window down, lock the door with the switch on the door, close the door. Wait for 2 minutes (you do not need to wait this long, this just plays it safe), reach your hand through the window and open the door using the handle without pressing the unlock button(this sounds like what you were doing). If opening the door does not set off the horn, then you have no factory alarm. The theft light on the dash is an indicator for the PATS system, not an alarm. Hope this helps. Keep us posted.