So, to disconnect a car alarm that keeps going try unlocking the doors, enter your car, and the alarm is still on, start the car and drive. However, if the alarm persists, the following are some advanced options you could try on " How to disconnect a car alarm that keeps going off ". Jun 29, 2011 · The most typical reason for a car alarm randomly going off like you say is actually because of the battery in the car. When batteries get extremely low and the alarm system is pulling power from the battry when the car is off it will get an interrupted feed of power and think that it is being stolen or something along those lines. Jun 03, 2016 · Step 1: Check your key fob battery. A car's anti-theft system may activate if your key fob battery is dead and hasn't disabled the system. Make sure the battery is installed correctly in your key fob. The biggest harm that can result from alarm fatigue is that a patient develops a fatal arrhythmia or significant vital sign abnormality that is not noticed by the clinical staff because that patient's heart rhythm monitor has been plagued with false alarms. Imagine a neighbor who has a hair trigger car alarm that goes off all the time. Fully charged voltage. A fully charged car battery voltage should be 12.6v or above, this is with the engine off. To get a true voltage reading of the cars battery it is important to measure the voltage after the car has been sat for a period with the engine off, preferably overnight, this provides you with the “car battery open circuit voltage” or also know as the “resting voltage”.