Got the car back from paintshop on Wednesday and ever since then l've had on/off alarm issues as the alarm just goes off on its own accord. Replaced the battery and for 2days its been fine, but about 2hrs ago it started going off again. Even when l completely disconnected the battery it still kept going. I've used the 4 number reset to no avail, its quiet at the mo but l'm worried it will go off again.
As l say battery is disconnected at the moment. Has anyone got any clue as to what l can do to rectify this problem. Any help/advise greatly appreciated.

 

Should have added its a 2001 Impreza bugeye.

 

And also should have said that despite the alarm going off l still managed to start the car upon which the alarm stopped but started again when l switched the ignition off.

 

Could be the battery backed siren, they are prone for water ingress which fry the circuit board, £57 plus vat from main dealer.

 

Cheers Inviroman I'll get that checked out.