E39 Alarm Problems
I have seen several threads for the alarm going off at random. My E39 530i started the same issue. I replaced the hood switch and it still went off at random. I unplugged the interior sensor, and it still went off at random. I removed fuse 48 from the trunk fuse panel, and even though siren would not sound, lights would still flash while alarm was going off at random. Come to find out that there is an updated hood switch, that originally came off the X5, with a longer plunger. When I had the alarm code read, it said the hood was opened 31 times. I picked it up from my local dealer for about $18 and no problems at all now. Hope this helps some of you.