It is usually the microswitches in the door locks, or boot lock.
Sometimes it can be the bonnet switch.
Another thing to try, is press the button that disables your interior sensors - I've had a car spider setting an alarm off.
Try this first as it's quick & free.
Mr Bodge-It
May 2023
Automatic Answer
We may have found other answers which could help you.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix car alarm systems.