E39 Car alarm going off randomly?

It was definitely the siren batteries. Once removed, the battery has not died once nor have the lights been seen flashing. I am once again gaining confidence that I can go to my car and it will actually start versus being met with a dead battery.

I have received the batteries and will wire them into the siren, reassemble it and install when I get time; I'll try to post pics to help explain.

Hope no one else has to go though this, but if they do, at least there will be a post to help them.

That is horrible. For my car, it was a weak car battery that caused it.
Once I got a new AutoZone battery, everything was back to normal.

I have my car alarm going on and on too. I've read an article about car alarms and code grabbers but I don't believe that someone would try to unlock my car with a grabber. Is it really possible?

I simply can not believe this POS car.

AFTER disconnecting the interior sensor, hood sensor and completely removing the siren assembly...a workmate comes to me yesterday and asks "Are you car's lights supposed to be flashing?.

Evidently there is still something activating the alarm system but I have no idea what it could be. I've read online from people stating their car had dirty metal contacts on the doors but when I looked at the entire door perimeter I did not see any.

Can anyone on this site list all of the sensors that make up the alarm system on a 528it?

Begin rant...I am so sick of this car and the myriad of problems associated with owning a BMW. Between the crap gas mileage, outrageous maintenance fees and parts prices what exactly is the allure to owning these cars? I just don't see it. Problem now is that this POS has depreciated 70% in 4 years so it's about worthless to trade in on a decent reliable car. Rant over... I now feel slightly better.

Originally Posted by EconoBox

That is horrible. For my car, it was a weak car battery that caused it.
Once I got a new AutoZone battery, everything was back to normal.

I reiterate this.
How old is your battery?
Mine was only 2 years old.
Replace the battery.

Originally Posted by EconoBox

I reiterate this.
How old is your battery?
Mine was only 2 years old.
Replace the battery.

I reiterate, I had the complete battery and charging system just checked...all good (battery is one year old).

No one has anything telling where the alarm sensors are? (Hood, siren, interior roof sensors have all been taken out of the picture).

Originally Posted by cagoguy

Before making any assumptions and shelling out $$ on an interior sensor, try disabling the under-hood sensor. It's a hugely common problem on E39s.

Lots of discussion on it here:

Hood Sensor / Alarm issue

Try pulling the plug. See if the alarm still goes off randomly. This doesn't affect your main door/interior alarm sensors in any way.

this is what caused my alarm to go off when i first bought my car. i just unplugged it too. hasn't gone off randomly since then