911 Carrera 1998 - alarm recently activated whilst car locked and unattended. Would not turn off even though remote unlocked doors. Eventually stopped and drove home as normal. Once the car is stopped and door shut alarm arms itself with high pitch tone and eventually goes off. Remote won't stop it and engine will still start whilst alarm going off! Any ideas?

Hi Binscall.  Welcome to the forum.  I hate electrical gremlins.

Take a look here and see if there's something that helps with the fault finding

www.myporsche911.co.uk/upb/viewtopic.php?id=34&t_id=17