What's wrong with my BMW alarm?

[Flycaster]

When I got my Z4, I had put in an original BMW parts alarm system-the full system which included the cabin motion detector. System has worked fine for these three years, however today it acted strange. About 10 minutes after parking the car with top up and windows closed, no other cars near mine, no one touching the car, a friend told me that the lights were blinking. Pressing the key's open door button, shut the alarm off. I opened and closed the doors and reset the alarm with the key. A few minutes later that alarm sounded again. This time I opened and closed doors, the trunk and the hook, set the alarm. I think it went off again. Did every thing again, and it didn't go off. Drove home about an hour after all this started, while in the garage with the top up and windows down, I set the alarm. That was 4 hours ago and no alarm going off. Could you tell me what may have set the alarm to malfunction? Loose wires? I doubt it as all wiring is done by BMW connectors. Could it have been some kind off electric/microwave signal in the area? I've been parking the car in this area for three years without this problem.

[Yal]

there have been a lot of problems with the hood switch

[Flycaster]

Yeah, that's what I've read on another forum. I've jiggled the switch and since then the alarm hasn't gone off on its own. Any idea what its part number is and where I can get a new one (don't want to by a whole new alarm system)?

[rosierobins2003]

same thing happened to my alarm, the dealer replaced the switch in the hood. others have had the same problem. my advice is to get an appointment scheduled quickly. I had to stop using it because everyone at work is aware of my car and kept telling me the alarm was going off.

Rosie