The answer is "you dont!" its most likely the factory fit with the "powersounder" siren which will continue to squeal even if you unplug it, most likely the powersounders rechargable battery is the problem, it senses the voltage in the battery voltage dropping and registers this as an intruer attempt, will probably need a new siren, failing this it could be the ultrasonic sensors at the door pillar/rearview mirror depending on the model. The best way to find out for sure is to go to your local Vauxhall dealer/ specialist. ask them to put it on Tech2 and interrogate the alarm trigger list, this will give an extensive chronological list of times dates and which component caused the alarm to sound, this should pinpoint the fault within a few minutes, and dont let them fob you off by telling you they can't because they can, also it only takes 10 minutes to access the Trouble code/trigger list, so dont let them tell you it takes hours because they will try and charge you a mint.
Spannermonkey, May 2010
