Trying to remove an after factory alarm system

diognestics

Depending if it is a aftermarket or a factory alarm, they should all have fuses that can be removed. By removing the fuse, you may lose your keyless entry option. Most aftermarket alarms have a siren that is usually mounted under the hood in the engine compartment area. I've seen where people have cut the wire going to the siren to disable it but keep the power going to the alarm system to keep the keyless entry still functional if it came with the alarm system.
Factory alarms usually use the existing horn for the alarm. If that is the case, you might need someone who is experienced to disable the circuit so that the horn will not sound if alarm goes off but the horn will still be functional when needed. Hope this helps.

Now im not sure since the manual says your model has the same alarm system as the 328i and on the 328i you can remove the module to disable by doing the following. you can unplug the control module. It is located under the glove box. Climb under the dash on the passenger side and remove a few screws on the trim panel under the glove box. Theres a black control module with a green connector. There should be a lock tab on the connector. press the lock tab and pull out the connector. The alarm should now be disabled. But if it has the special transponder key this may not work.
But if the only reason you want to disable it is because of the motion sensor setting of the alarm for no reason there is a solution for this. To disable the motion sensor, hit the lock button to arm, then hit lock button again within four seconds to disable motion sensor. Red light on rearview mirror should flash four times, then pause, then start flashing on regular intervals. this is most likely the reason if your having the issue where the alarm goes off every 20 minutes.
If you want to completely remove it below is a wiring diagram taken from the manual for you alarm system.
this is from the manual its the alarm wiring diagram.
Battery Constant 12v Positive Wire ( ): Red/White or RedBattery Constant 12v Positive Wire Location: Ignition Switch Harness
Starter Positive Wire ( ): Black/Yellow or Black
Starter Positive Wire Location: Ignition Switch Harness
Ignition Positive Wire ( ): Green
Ignition Positive Wire Location: Ignition Switch Harness
Second Ignition Positive Wire ( ): Purple/White or Purple
Second Ignition Positive Wire Location: Ignition Switch Harness
Parking Light Positive Wire ( ): Gray/Purple and Gray/Yellow. Use Both Wires. This vehicle has a dual parking light system that will require 2 extra relays.
Parking Light Positive Wire Location: At Headlight Switch
Power Door Lock Positive Wire ( ): White/Red
Power Door Lock Positive Wire Location: At Factory Alarm Plug. The alarm plug is a black 12 pin plug located just behind the glove box.
Power Door Unlock Positive Wire ( ): Blue/Red
Power Door Unlock Positive Wire Location: At Factory Alarm Plug. The alarm plug is a black 12 pin plug located just behind the glove box.
Door Trigger Negative Wire (-): Brown/Gray
Door Trigger Negative Wire Location: At Factory Alarm Plug. The alarm plug is a black 12 pin plug located just behind the glove box.
Domelight Supervision Wire: Turns On With Unlock
Domelight Supervision Wire Location: N/A
Horn Negative Wire (-): Brown/Red or Brown/Yellow
Horn Negative Wire Location: At Steering Column Harness
Tachometer Wire Negative Wire (-): Black
Tachometer Wire Negative Wire Location: At Instrument Cluster
Brake Light Positive Wire ( ): Blue/Red or Green/Red
Brake Light Positive Wire Location: At Switch Above Brake Pedal
Factory Alarm Disarm Wire (-): Disarms With Factory Remote Only. Factory Alarm Disarm Wire Location: N/A
Factory Anti-Theft System: Transponder Anti-Theft System, Requires Bypass And Extra Ignition Key. The 1997 model year vehicle may require a bypass module and an extra ignition key, if vehicle is equipped with a special key from BMW.
Factory Anti-Theft System Location: Transponder At Ignition Switch Tumbler
if you require further assistance please let me know and i will help assist you from there. Thanks, Midwest-Tek

you cannot remove the factory immobilisor,but you can remove an aftermarket alarm

Why not just get the factory PATS System working correctly. You can't remove the factory system,it's an integral part of you vehicles systems and processors

You can get new remotes and program them!!

Doesn't by opening the hood, that will disarm the alert system? Is it factory installed system? Try removing the fuse for the alarm system (near the system box - probably around the brake light switch). There must be a crossed wire somewhere.

Is this a factory installed alarm system? If so, unlocking the driver door with the key will allow the car to start. If not then you will have to remove the aftermarket alarm system to start the car.
If you have a factory alarm system you can get a new FOB (key chain alarm button) from a ford dealer, but it must be programmed using a scanner , before it will work in your vehicle.

for a factory alarm the only way is to lock/unlock doors(with key) unless some one knows how to disable the alarm altogether. if alarm is not factory just find the box and remove alarm system (you may need to reconnect some wires if it has starter disable as a feature)

First question , is it a FACTORY alarm or an AFTER MARKET alarm. Regardless, I haven't met an alarm yet, that protects the radio.. My guess is, that if it is an aft/market alarm, inadvertantly placed the system in the "VALET" where it doesn'i work. Let me know if you disconnected battery, and are there alarm toggle switches.

Why would you add another alarm?? I recommend you remove the aftermarket alarm, it is the cause of the issue, there is no fix, the factory alarm can't be disconnected, it is an intergal part of the starting system.