Car Alarms: after market alarm goes off at a particular time at night, body control module bcm, corvette coupe

Question
Hi, I have a weird problem and I'm sure the neighbors hate me by now; I took my car to the shop that's installed the alarm twice now with no luck. The alarm keeps going off at around 3:30 in the morning almost every night for no reason. I have videocamera pointed to it and a digital recorder attached so I can replay the events that caused it to go off. There's nothing visible, it just all of a sudden goes off at almost the same time, time after time. It's installed on a 2000 Corvette coupe. I'm thinking, could it be a problem that it is attached to the car computer and the computer resets (?) itself every night or something? I'm at a loss here and so are the guys who installed it. Any clues would be greatly appreciated. Thanks.

Answer
Ok, from the explaination, the door trigger wire is either
only reading one door, and the other is triggering
the alarm late at night after an internal diagnostic
from the onboard computer. I think you are correct
on that point.

There are 2 door triggers on the 2000 Vette.
The wire colors are gray/black & black/white (-),
located in the body control module -BCM- in the
passenger footwell under the carpet.
I would have the shop re do that if unsure.
Use both wires, but add a diode to isolate
to help with the faulsing.

The other way to completely take this issue out is
to take off the door trigger wires, and use
a 2 stage microwave motion sensor instead.

That will definaely stop the car's computer reading
an open circuit while armed.

Let me know what you discover.

ALARMTEK
CARALARMSTORE.COM