factory fitted alarm.

[david57]

Hiya, I have a 1990 320i se with a factory fitted alarm and a 13 button OBC, I have replaced the display lights, it works well and I am able to use the immobiliser. I have reconnected the 11 pin wire plug to the siren, the alarm works when a door is opened, but what I do not know is how to turn the alarm off an on ?
ie do I need a one button remote, can any one help me with this.

[Brianmoooore]

Do you mean the alarm and immobiliser included in the OBC, or a separate, additional unit?

[david57]

hiya, no the alarm is a separate unit, the OBC controls the immobiliser, but they are all wired up together, the older sirens had a key for on/off, mine dose not, so clearly i need a way to turn it off before i open the car,

[Brianmoooore]

The 13 button OBC has an integrated immobiliser which is activated by entering any four digit code of your choosing with the ignition switch in the accessories position. It is deactivated by turning the ignition on when you return to the car, and entering the same code again. The alarm associated with it will only sound if three attempts are made to start the car with the immobiliser activated.
There is no such thing as a factory fitted alarm/immobiliser. They would have all been fitted by the supplying dealer, and there are variations depending on the age of the car (mainly applies to late models), plus a couple of 'BMW approved' alarms were offered.
Unless someone has been very creative with the wiring, these two immobiliser/alarm systems are entirely separate.
All the BMW and BMW approved models I can think off have a key to switch the alarm off permanently, but normally they would be controlled by a remote fob.

[david57]

Yes as I said the 13 button OBC is working well, I can set the immobiliser by entering a 4 digit code, I have tested it, it works, lights flash, the alarm siren sounds, I am happy with that. The alarm unit and dash movement detector is all as was factory fitted by BMW, nothing has been added, all i need to no is how to reset the alarm or do I need a remote, As it states on hear, BMW used what ever they had to hand when needed for there SE models,

[Brianmoooore]

You will need the correct remote fob, hard coded (solder bridges and cut copper tracks) to your alarm to set it. The key switch is only to turn it permanently off.