Astra Alarm Problems

[goalie]

I have an Astra 1.7DTI Estate 2002 reg. According the manual one click
on the key should lock without activating the alarm, two clicks should
then activate alarm. However my alarm is activated on first click or on
one turn of the key. Is this right? Does the manual lie. Is there a
way round this so I can lock without activating the alarm? Also
pressing the two internal reading light buttons do not deactivate the
sensor. Are these problems common, is there a simple fix? As per usual
first sign of hot weather the alarms keeps going off (I have shut all
the air vents and windows and there are no spiders or moths inside per
other messages) so I'm having to leave car unlocked all day.

Advice appreciated.

 

[me140]

Have you had any fault codes and alarm codes read?
The dealers Tech 2 will tell you what the last 9 alarm activations were so
even though you are blaming the interior sensor it might well be the power
sounder that is the problem cos they are always going wrong.

 

[mikeFNB]

second that

try putting cling film over the motion sensor(s)
then try again.

mike