2002 astra van ?

hi gary. Up inside the front passenger side wing is the alarm unit. Take the wheel off for ease, remove the plastic wheel arch liner and the alarm unit is mounted up on the inner wing. Take it off - think its screwed on, disconnect wires too. Inside the unit is a battery, which when flat causes the alarm to go off. Prise open the unit, and replace the battery. Hope this is the fix to your problem

andy
February 2010