7 Reasons Why Car Alarms Will Continue Depending on Random
Car alarms without a reason are a common problem reported by many people. The problem is that people get even more annoyed when they sleep, and suddenly the alarm in their car runs out for no obvious reason.
Luckily, the alarm doesn’t run out of thief every time. Installation or other reasons may be incorrect, which can lead to alarms. What could randomly lead to a car alarm?
The most common reason why car alarms always fail randomly is due to low battery voltage or misconfigured motion sensors. It can also be caused by a failed bonnet resource sensor, a door locker, a failed key FOB, or an incorrectly installed car alarm.
In this article, we will consider the reasons why car alarms continue to go off. We’ll also talk about what we’re doing about it and see some related questions. Here is a more detailed list of why car alarms continue.
Why car alarms disappear randomly?
1. Low battery charge or dead car battery
Bad or low battery charging is a wide range of reasons why car alarms break down at night. If you hear your car alarm goes off in the night and your car battery is dead in the morning, it can cause your car battery to get worse.
If the car alarm goes off but you can start the car without any problems, it’s probably something wrong. You can test your car battery with a car battery tester or use it only on a multimeter to see how good it is and replace it if it’s bad.
2. Sensitive impact/movement sensor
An overly sensitive impact or motion sensor can trigger an alarm. In this case, if a dog or cat gently touches the car, the car’s alarm may turn off. The types of impact and movement sensors available in cars depend heavily on the model of the car. If the car alarm is an aftermarket alarm system installed in the car or a car alarm from a factory.
Some car models with car alarms from the factory can use diagnostic scanners to program the sensitivity of the shock and motion sensors. This is often necessary for cars like Audi and Volkswagen, and sensors are hyper-sensitive to the factory and can be unnecessarily able to drive out. Some aftermarket car alarm systems also have adjustable sensors. For more information, see the car alarm manual.
3. Incorrect food bar sensor
Modern vehicles have bonnets that cause an alarm when someone tries to open the hood of a car. Depending on the condition of the car, dust, dirt and debris are very likely to collect where the bonnet lock sensor is located, which can lead to an alarm.
To fix this issue, look for the sensor and clean it. If you still hear the alarm noise, it may be that someone has tried to operate the sensor, or that the sensor is damaged. If you think it’s broken, replace the sensor. The bonnet resource sensor can mostly be found in the bonnet lock, but it can also be installed externally.
4. Error door lock sensor
Just like the bonnet lock sensor, car alarms monitor the car doors and prevent anyone from opening the door. Therefore, a broken door lock sensor can lead to a car alarm. Door lock sensors are often installed on door lock drives, but they can also be installed outside the castle. Finding a broken door lock sensor is only difficult if it occurs from time to time.
A door lock sensor is usually two wires that are circuits that open when the door is open, or closed when the door is closed. This makes it easier to measure with a multimeter. However, door applications are often found on the door, so if you don’t measure from the control unit instead, it can be a little difficult to measure.
5. Faulty Key Fob
The key fob, also known as a car remote key, is a device used to lock/unlock your car doors and even start the engine with the push of a button. Since the key fob also has controls linked to the car alarm system, a malfunctioning or faulty key fob can send an incorrect signal, which may trigger the car’s alarm.
You can check and replace the essential key fob batteries or reset the device to fix the problem. When you have replaced the batteries, and you have communication problems, you may have to reprogram your key fobs in some situations.
6. Incorrect Installation of the Alarm
If you have recently installed a new car alarm system and noticed that the alarm keeps going off for no reason, it may be because of incorrect installation. If you let a mechanic workshop install it, go back and explain your problem, and if you installed it by yourself, it is time to recheck the installation manual and double-check everything.
7. Bad Alarm Control Module
Car alarms installed from the factory often have an integrated alarm control unit and a main electric component control unit, so a faulty control module is not common.
An aftermarket car alarm often has an alarm control module that controls all sensors and switches; if this control module fails, it may cause the car alarm to go off now and then.
What to do if your car alarm keeps going off
While trying to diagnose a car that keeps going off can be quite tricky without the right tools, there are still some things you can try to see if you can fix it by yourself. While some of them require some special tools, you can follow the procedure here:
1. Charge the battery & Check the charging voltage
The first thing you need to do is to check the voltage in your battery with a multimeter. It should read somewhere around 12 to 12.5 volts when the ignition is on. If it’s under 12 volts, it is definitely time to recharge the car battery with a battery charger.
As long as the alternator is doing its job correctly, your car battery should not discharge if you drive it every day. Start the engine, let it run, and recheck the battery voltage with a multimeter at idle. It should not read between 13.5 to 14.5 volts on idle if everything is correct. If you find that it is reading between 13.5 to 14.5 volts on idle, you may have a bad alternator which is causing the car battery to drain.
2. Check for any trouble codes with an OBD2 scanner
If everything seems fine with the charging voltage and the car battery, it is time to look for any trouble codes with a scan tool. You can either get one yourself or lend it from a friend or let a workshop check the trouble codes for you. A cheap scanner will not be enough to check for any trouble codes related to the car alarm because most of them can only read trouble codes from the engine control unit.
Also, if you have an aftermarket car alarm, you can’t check for any trouble codes in the car alarm system with a standard scanner. However, if you find any trouble codes, you need to start troubleshooting wherever the codes say the problem is.
3. Lubricate all door hatches & locks
If you can reach the connectors, spraying some electric cleaner into them is also a good idea. However, they can often be quite challenging to reach without taking the whole car apart.
4. Check the sensitivity setting
If your car has a car alarm installed from the factory, there is a big chance that the problem lies with the sensitivity settings for the shock or movement sensor.
In some car models, you can reach these settings from your car’s display settings, so it’s a good idea to check the owner’s manual for any signs of these settings. If you can find them, you can try to reduce the sensitivity.
5. Change the key fob battery
While this issue will most often not cause your car alarm to go off, it can happen in some rare cases. Key fob batteries are usually very cheap and relatively easy to replace in most keys. Again – check your owner’s manual for instructions on how to replace the key fob batteries.
If you have tried everything above, but your car alarm still keeps going off, there is not much more you can do without more profound diagnostic knowledge. Therefore, it’s time to use professional help from a workshop with the proper diagnostic tools.
Where are car alarm sensors located?
You will also find motion sensors and other types of trigger sensors, depending on the car model and how modern it is.
Can you turn off a car alarm permanently?
If your car has an aftermarket car alarm, it’s often quite easy to remove the car alarm if you don’t want it. It depends entirely on the car model.
How long will a car alarm go off?
Modern car alarms typically go off in 15-30 second intervals, over a period of 5-20 minutes, depending on the car model. Older car alarms could go on for many hours until the battery has discharged.
The best thing to do when your car alarm keeps going off is to check the battery first. If the battery is good, then you want to make sure all the door locks are working properly.
Don’t ignore your car alarm if it goes off frequently, as it could be an indication of a more serious problem. If you feel that you do not have the knowledge to find out what is causing the problem, it may be a good idea to contact a professional.
