Strange Alarm Issue? Alarm wont Disarm at Mornings!

[MoJoJoe 46]

My car(1995 328i) has an Strange Alarm Issue, I think it may be something pretty common so please give me your inputs.

Previous owner had the alarm cut off, never told me why but from the wiring I could tell it must have been an after market unit, so I installed an alarm myself and had everything working and it would work fine for a few hrs but then the thing would not disarm. Had a professional install another alarm for me and its now doing the same thing. it will arm and disarm fine but if left for a few hrs the signal from the remote gets weaker and overnight it just wont disarm. unless I trigger the alarm off and reprogram the keys.

My Battery is new and fine, and I have fixed the bad wires in the trunk harness that breaks. something is telling me there is something thats happening in the car when left for sleep mode or some previous alarm RF frequency in the rear view mirror or something that makes the communication between the alarm and the fob very hard and then makes it forget.

Is this a common issue I think it maybe an interference or the temperature or something? maybe a capacitor somewhere? can anybody please help?

Edited May 28, 2014 by MoJoJoe

[Neal 544]

You may have already cover these areas but I'd check the following

The alarm should be connected to a constant power rail , not an ignition circuit that drops after sleep mode.

Does the alarm module rely on some kind of rechargeable battery that has failed that keeps the memory running (like cmos batteries on PC motherboards of yester year)

What remotes are you using , bmw factory or aftermarket alarm ( Clown noise is infrared btw ) Depending on remote you might be running infrared or 433mhz radio

Are you using a factory or after market alarm ?

Edited May 29, 2014 by Neal

[MoJoJoe 46]

Hi Neal, thanks for trying to help. its connected to a RED (constant) I also had a professional do the second alarm for me, I got a multimeter and did the alarm install on this first time around myself, also did it on a few other cars. have all the wires figured.

I have a diamond shaped key with a little yellow light(torch) on it, the car does not have a factory alarm, the alarm I have right now is a mongoose, the alarm module can remember things so even if you disconnect the battery it doesn't matter and keys dont need to be reprogramed, no cmos style batteries inside when I opened the unit.

So I was reading and there Fuse 7 is labled "Infrared" ( burglar alarm) ?? I wonder what it does because I have it disconnected. (Central locking is working as the fuse for that or windows rolling seems to be 43). think its some kind of security related feature? that works in conjunction with the other features? i was reading and found this "RF receiver is in the rear view mirror, and it downconverts the 433MHz to lower frequency data for the ZKE" so could this be somehow interfearing with my alarm/ i will leave it like this overnight and then see tomorrow if the problem goes away and if it does I will reconnect the fuse and try again, could had just been bad batteries or a hood pin switch which I unplugged as well.

i also put new batteries in my alarm remote and reprogrammed them, has been working nice the whole day now hopefully this sorts my problem, so far so good, if it works fine tomorrow then its good as gold.

Edited May 29, 2014 by MoJoJoe

[Ahmedsinc 414]

you've got the 328i, right? you've got EWS. Google it

[MoJoJoe 46]

you've got the 328i, right? you've got EWS. Google it

ah, yes i know of that, so fues 7 controls that ring around the ignition and I need it for the car to start? could that had been messing with my alarm systems?

will put it back on tomorrow. most of my fueses were 32v strangely. shouldn't they be normal 12v ones?

[hotwire 352]

You seem to be confusing yourself somewhat. Has you car got a factory alarm or not? I doubt it has had one.

Your explanation is also a little confusing.

Firstly - why did you not get the professional installer to recheck it if his install didn't operate correctly?

I gather you are using separate Mongoose remote/s. The battery in it/those would be the first thing to check.

The module simply needs 12v constant, ign & earth to operate. Obviously doesn't need the ign supply to turn it on/off.

Don't concern yourself with fuse designations - no relevance to your situation. EWS system will have no influence on the aftermarket alarm either.

Fuse rating - you are concerned with amperage rating - not the max voltage

[MoJoJoe 46]

You seem to be confusing yourself somewhat. Has you car got a factory alarm or not? I doubt it has had one.

If you read the first few posts I have said it over and over again that I dont have a Factory Alarm, I saw no signs of a factory alarm and the previous owner had cut off the alarm the car shipped with which from the led in the dash aswell as the wiring(tapping here and there) I could tell was not factory either.

The alarm I have mongoose which i bought from reretardme.

Your explanation is also a little confusing.

Firstly - why did you not get the professional installer to recheck it if his install didn't operate correctly?

I installed a different alarm, an old one from the 90's I had sitting around, it also only had 1 remote. After installing and programing then that was doing this same thing, so I bought the mongoose and had the professional installed install it when I got stuck with the mongoose outputting the 12V + to the central locking.

I gather you are using separate Mongoose remote/s. The battery in it/those would be the first thing to check.

The module simply needs 12v constant, ign & earth to operate. Obviously doesn't need the ign supply to turn it on/off.

Don't concern yourself with fuse designations - no relevance to your situation. EWS system will have no influence on the aftermarket alarm either.

Fuse rating - you are concerned with amperage rating - not the max voltage

Yes. I got 2 remotes with it, one had bad batteries and the other low. So I ordered some batteries CR2016 x2 on each remote. Installed them yesterday and programmed the mongoose with the remotes and It worked fine the whole day and this morning the alarm works fine! I disarmed it from inside my house 20 feet away! You are right, so seems its was a battery/remote related issue with this alarm and most likely my other alarm as well and had nothing to do with the cars wiring or the alarm head. I have also disconnected the hood pin so wonder if that had anything to do with it. I will reconnect and test again tonight. But most certainly it was the batteries in my remotes.

thanks guys

Edited May 29, 2014 by MoJoJoe

[hotwire 352]

Yes it will likely have been the remote batteries causing the issue. That said, remotes have been known to drop out of sinc with the modules at times, but this is normally a constant until they are re associated.

Another issue can be interference frequency from other sources in the vicinity. Have seen this a few times in recent history. Shows up when the system auto arms/immobilises & then wont turn off via remote.

Switches - bonnet/boot/doors will have no bearing on alarm turning on or off.