If you set the alarm (i.e. lock the car) and then disconnect the battery, the alarm will go off. If you disconnect the battery when the alarm is not set (i.e. when the car is unlocked) the alarm will not go off.
(So don't try to nick a locked one).
disconnect battery ,but before doing so write down any codes required eg radio code etc
Some alarms systems have a protection function which will prevent starting the engine is somebody tried disconnect the battery and connect it again. Also what might happen is that your alarm system doesn't have memory in the case if you disconnect the battery. Thus, if you do disconnect the battery it will reset the alarm system to the default factory settings. By default, the alarm system will block starting the engine.
Under the hood !
If you are the owner you should know that if I tell you how, everybody will be able to disconnect the alarm of a z3 and your car will be vulnerable. So use the remote with the white buton.
take the battery back out
AnswerAfter 1997, the battery is in the trunk. Lift up the mat and remove the two screws on the black plastic top then disconnect the black wire first then the red... lift battery out.... but if you have alarm fitted put your ear muffs on!!! Drop in voltage will trigger it. Undo long screw nearest to you that holds battery in place.
First of all disconnect the battery.
Disconnect ground. Disconnect positive. Attached chain to back of Semi-Truck, attach chain to battery. Drive the truck away.
If you disconnect the battery (or the battery is very low and a relay will automatically disconnect the battery) you need to input the code for the radio. Maybe you battery is too old or too discharged.
Disconnect battery.
Disconnecting the battery is the easiest way. Then disconnect the airbag.
disconnect the negative battery terminal for 10 minutes.