Car Alarm Keeps Going Off: A Complete Guide

Car Alarm Won't Stop

An alarm is an essential part of the car’s anti-theft system. The car alarm goes off once it seems our car is in danger of being burgled or stolen by an unauthorized person. The loud sound produced by the car alarm will alert us wherever we are so we can act accordingly just in case something fishy is being carried out in the car. 

This is a really great feature as it doesn’t only grab the attention car owner but also every single person around the vehicle at that time. The car alarm produces a loud and attention thieving sound, which is excellent and all but can become bothersome if the car alarm keeps going off repeatedly for no reason at all.

It becomes even more infuriating; especially at night when all is calm and quiet, then all of a sudden, a loud noise that can lift you off your bed like you are having a nightmare. This is one of the car troubles that affect not only you as the car owner but everyone around as well, and it’s something you do not want to encounter every night.

Car Alarm Keeps Going Off: Causes of This

A car alarm keeps going off for different reasons. For whatever reason, let’s understand how the car alarm works. Regardless of the kind of alarm (pre-installed or post-installed), they work using the same mechanism.  

In the simplest way possible, the car alarm works employing voltage sensors. When there is an unexpected voltage drop, the sensor picks the signal, and the alarm produces a loud sound. Several reasons why your car alarm keeps going off can be discussed under two factors: intrinsic and extrinsic factors

Internal Factors

Intrinsic factors are those factors found within the car that can be the source of the issue that makes the car alarm keep going off. They include the following factors:

1. A Defective Car Remote (Key Fob)

The key fob is a simple device that allows you to lock and unlock your car at the push of a button. The key fob is also used to set the car alarm manually, so if anyone without the key fob tries to unlock the car, it prompts a response from the car alarm. 

A defective key fob may send the wrong signal to your car that may set off the alarm. Most times, you do not have to touch or even be close to the key fob for it to send the wrong signal to your car. 

What To Do: If you notice that the key fob is defective, the possible way out is to change the batteries to your key fob. If you can get a new key fob after changing the battery and still experience the same issue, you can consider other factors below.

2. Low Car Battery

A low car battery can also falsely activate the car alarm. As mentioned earlier, the car alarm works with voltage sensors, so if there is a sudden voltage drop, it can go off. This often occurs when you try to start your car on a low battery. 

What to Do: Simply recharge your car battery. If the battery’s voltage is less than 12.5v, it is considered low. You can use a portable multimeter to check the amount of voltage your car battery is producing to be sure if it’s actually the battery causing the false activation of the car alarm.  

3. Bad Battery Cables & Terminals

Aside from a low or dead battery, other intrinsic factors are bad battery cables or rusty battery terminals. These factors also lead to the production of low voltage, which may trigger the car alarm falsely.

What to Do: Have your battery cables and terminals checked by a technician. You can also try to clean the battery terminals yourself.

4. Super Sensitive Shock Sensors

The shock sensors are what make the car alarm go off when the car is exerted by a particular force in a particular manner. If the car’s shock sensors are too sensitive, it will unnecessarily trigger your alarm no matter how little the force is. 

What to Do: Look for the car manual to learn more about the range to set the sensors. You can also just twist it a little to adjust the sensors. If you don’t have time for this, take it to an auto repair shop.

5. Malfunctioning latch sensor

The latch sensor is a technology that comes with newer cars. It sends a signal to the car alarm when the bonnet is opened forcibly. A bad or polluted latch will accidentally send signals that will cause the car alarm to go off, which can happen at any time and very often.

What to Do: For a damaged latch sensor, take it to auto repair to have it examined by a technician. However, you will likely have to check to see if your hood is dirty; if that happens, then cleaning is the only option.

Car Alarm Won't Stop

Extrinsic Factors

These are external factors that surround the car. They include stormy weather, straying animals, people that keep hitting the car continuously, and you, the car owner.

1. Extreme Weather Conditions 

Many car owners and drivers have also been worried about the impact of the weather conditions, particularly the wind on the going off of their car alarm. So, they become curious and want to know if the wind can set off their car alarm.

To say that your car alarm can go off during terrible weather and that the wind can keep your car alarm not working is a no-brainer. Even though this might sound a little bit strange to many drivers, it is not unheard of because a terrible wind can shake a car to the extent that it sets off the alarm.

Usually, a powerful stormy wind with a tornado force could pull a lot of intense force towards your car and will make some components, including the alarm, not function. If this kind of wind blows intensely, your car shock sensor loses its sensitivity, making it impossible for the alarm to work. However, you can readjust your shock sensor to make it sensitive again.

In stormy weather conditions, you can park your car in a garage or a well-secured parking lot. Do not leave your car in the open to avoid the effect of the elements.    

2. Car Owner

It may sound weird that the car owner can be the cause of a car alarm to go off. Yes, the car owner can cause the car alarm to go off accidentally; this usually happens when the car remote is in a position where it has been tampered with by chance, all you have to do is reposition it.

3. Stray Animals

Sometimes what you find out is that stray animals can hit the car and cause the alarm to stop working. Concerning people and animals, the possible solution is to park your car in a position that will not be accessible by stray animals or people.

Deactivate Your Car Alarm

Sometimes, it becomes extremely difficult for you to immediately spot what exactly is happening that is making your car alarm go off. At that point, you can’t figure it what the cause is, the best thing to do is to deactivate the alarm system. This will help you look thoroughly into the entire system to find out where the problem lies.

Deactivating your car alarm is no rocket science. With four simple methods, you can have your car alarm neutralized in a matter of minutes to make it go off until you can identify why it did not work, to begin with.

Let’s look at the four possible solutions:

1. Lock & Unlock Car Doors

This sounds like a great way to disengage your car alarm and make it go off. With simple inserting of the car key, locking and unlocking, the alarm system can turn off as quickly as possible. Once the alarm system can recognize —and many modern alarm technologies work this way — that the right key has been inserted into the fob, it will automatically go off. The method also works if your car is using an electronic fob. All you have to do is to press the fob to unlock the button.

2. Start the Car

The second method you can use is to start the car. Once you can start the car, you are sending a signal to the alarm system that you are authorized to get into the cabin. The alarm will receive the signal and go off.  

3. Remove the Fuse

One other thing you can to turn off your alarm system for the time being (until you can find out while it turned off in the first place) is to disconnect the fuse that connects the alarm to the electrical part of your car. Although this may be an extreme method, it does work perfectly. Meanwhile, you will need to find out the location of the fuse that powers the alarm. Typically, it can be in the engine compartment or right inside the cabin. With the owner’s manual, you can find the location of the fuse and remove it. You can replace the fuse with a new one to see if the problem is resolved.

4. Disconnect the Battery Terminals

You can also remove the battery terminals to see if it resolves the alarm hassle. If the first three methods fail to fix the problem, you may just have to try out another method. If you disconnect the battery terminals in your car, it allows your alarm system to rest and go off. Do not use bare hands to carry out the disconnections. Instead, use pliers or a wrench and a pair of safety gloves when trying to release the bolts and nuts from the terminals. Once the computer can reset the system, you can reconnect the disconnected negative terminals. 

Frequently Asked Questions

Q: What is a car alarm proximity sensor?

A proximity sensor detects when your car gets too close to an object. They send a signal to the car alarm system to alert you. There are proximity sensors that can set off the car alarm when you are not around your car. This is very good for convertible cars as you can arm your alarm even with the roof down.

Q: Should my car alarm be Approved by Thatcham and What does it mean to say that?

The direct answer to your question is that your car alarm must be approved by Thatcham. When it is said that a car alarm is Thatcham approved, it means that your vehicle alarm has gone through rigorous testing to check the reliability of the alarm system by the Thatcman Company. The award for reliability is given in categories depending on how the car alarm works. Apart from reliability, the approval also implies that the car alarm is suitable for use in the public.   

Q: What is a car alarm tilt sensor?

This is a new feature that sends signals to the car alarm when the car is lifted. Some car thieves will not break into the car instead they tow the car or place it on a low loader. This feature also prevents the wheels from being stolen.

Final Thoughts

There is no doubt that it can be both risky and annoying when your alarm system goes off, especially when you expect it to alert in the event of theft.

A car alarm that goes off is one of the car issues that can be fixed by you, but if after trying and there is no change, and then take it to a recognized auto repair shop. Fixing it as soon as possible is the best option, for it could lead to other problems like a dead battery.