Originally Posted by GDC-SRT
I should have said, that if your alarm is sounding, and you disconnect the battery, the alarm will continue!
You are right, just tried it and sure enough the siren continued. This is why:
page 1556 of service manual
"SIREN
The vehicle theft system alarm Siren contains a built in rechargeable battery back up and can sound if its electrical
circuits are disconnected or if the vehicle battery cables are disconnected. The Siren can also sound if the electrical
circuits between it and the CLP/SSM are disconnected. Once triggered, the Siren can only be silenced by unlocking
the vehicle with the RF key transmitter or by unlocking the vehicle with the mechanical key."