Car Alarms: alarm sounding randomly, viper car alarm, shock sensor

Question
I have just purchase a Viper car alarm for my 99 Mazda B4000 pickup truck. The alarm goes off without any cause. It may be a couple hours before the alarm sounds, or just a few minutes.  Long before I purchased the alarm I broke the sliding part of the window in the back up the pickup and replaced it with plexiglass that slides shut, but does not latch. Does that have anything to do with the alarm going off?  

Answer
The systems is either reading an open door circuit (not the back glass window), is on the wrong door trigger, or,
the shock sensor is too high. I would take it back to the installer, explain the situation, and let him re do the
system, possibly turn down or off the external shock sensor, and then try again.

Good luck with it.

ALARMTEK