alarm randomly going off

hi all,got probs with an alarm that came on a car i just bought must be a scorpion cos thats whats on the key fob on back of key fob it says mpt 1340 dont no if that would be model of alarm...anyway my prob is alarm is randomly going off but it seems to work everything else fine locks doors/does window up/flashes indicators just wondered if any one might no what prob is or how to cure it it starting to do my head in  many thanks all

This how many (but not all) afermarket systems work----there is a feature that, after the alarm has sounded, it tells you which part of your car was "broken into"----the hood? trunk? doors? shock sensor?    Anyway, it's also a useful troubleshooting tool. Wait until it falses again. Disarm it, but do NOT turn on the ignition key----just look at the LED, and count how many times it flashes. This tells you which "zone" was violated. Now, turn the key on and off to reset the system, then close the door and arm it. Purposely set off the alarm in different ways, first by opening a door with the key, disarming the alarm, and counting the flashes.......... Again, use the ignition to reset it, arm it again, and open the trunk..........and so forth, until you learn which "zone" is which. After you know which zone is falsing, it will be much easier to work it out after that.

many thanks mate i give it a go