Originally Posted by JFawcett

Just unhook it.
Do you ever rush to the aid of some car that is clearly being stolen by it's owner?
They all eventually loose their minds and the alarms go off at the most inappropriate times. On my 87 560SL the alarm started going off driving down the road. On my 420SEL, the alarm went off only when opening the hood - even with the doors unlocked.
The combination of electronics, vacuum and age just doesn't bode well for the performance of the alarms.