Car System

Car Alarm Keeps Going Off!!! Why And What To Do?

Mike Cross
Updated Apr 17, 2023

There is probably nothing more annoying than a car alarm that does not stop. The constant and repetitive shrill is enough to make your ears bleed. The job of a car alarm is to protect your car, but why does it sometimes go off continually and is there anything you can do to stop it?

How does a car alarm work?

A car alarm system is designed to go off when it senses an intrusion. This is due to shock sensors that are designed into the car. They are designed to go off anytime a loud noise or force hits the car. Car alarms are also designed to go off if someone tries to open the locked door while the alarm is engaged.

Some cars use an alarm system that is voltage based. These types of sensors are triggered when there is a change in voltage, such as a door being opened and a light turning on.

Car alarms are turned on when you press the button on your key fob. The alarms are also turned off in the same way. So, if your alarm does not turn off, you have a noisy problem.

So, what can cause your alarm to keep going off?

1. Malfunctioning Key Fob

A malfunctioning key fob is a common cause of the car alarm repeatedly going off. If the key fob is not working properly, then it could be sending the wrong signals to your car. The mixed signals then cause the alarm to go off.

You should first try to fix this by replacing the batteries in the key fob. Simply open the key fob cover ad check the battery size. You should be able to buy replacement batteries anywhere batteries are sold. If you cannot find the right size, go to your local dealership and purchase them there.

If you still have issues after replacing the battery, try using a scanner to see if it will give you a code for the problem. You can also try and reset the key fob and see if that helps.

2. Check your car’s battery

The condition of your car’s battery can affect your alarm. This can happen in a few different ways. If your car’s battery is starting to die out, your alarm could go off when you try and start it. This was designed to alert the owner to the fact that the battery needs attention.

You can easily use a voltmeter to check the status of your car’s battery.

You should also check the battery’s terminals. If the terminals are rusty or corroded, that will prevent the battery from sending the needed amount of power out when you turn your car on.

Rusty terminals may also send out a low battery signal, which will cause your alarm to go off as well.

If your battery is running out, the good way to do is recharge it with the battery maintainer, it will help you alarm working correctly.

3. A Faulty Hood Latch Sensor

Your car’s hood latch sensor may not seem to be related to your car alarm system, but it actually can affect it.

If your car’s hood latch sensor is damaged or dirty, it can cause your alarm to go off repeatedly. If debris and grime are not regularly cleaned from the latch you will get build up.

This build up prohibits the hood from properly closing. This makes it seem as if someone is trying to open the hood of your car, and the result is a car alarm that goes off.

Likewise, if the latch is damaged. You will not be able to properly close your hood and the result is an annoying car alarm.

What Can You Do When Car Alarm Going Off?

What Can You Do When Car Alarm Going Off
What Can You Do When Car Alarm Going Off

When your car alarm repeatedly goes off, it can be annoying. However, it should be a relatively easy problem to fix by yourself.

The first step is to check the battery in your key fob. Open the key fob up and replace the battery with a new one. You can easily get a new battery anywhere batteries are sold. You can also purchase new batteries from a dealership, although they tend to be a bit pricier.

You can also try and reset your battery and see if that helps take care of the problem. If you have a scanner at home, try and see if it will give you a code to let you know what the issue might be. A bidirectional scanner might also be able to do a factory reset for your key fob.

Check the car batteries as well. If the car battery is running low on juice, this can cause the car alarm to go off. In actuality, this is a good indicator. It is easy enough to use a voltmeter to check the life of your battery. Car batteries can be purchased and replaced very easily as well.

It is also a good idea to check the battery terminals. Be sure to clean off any corrosion or rust. This buildup does affect how the power is distributed throughout the car. Anything that interferes with this has the potential to set off the car alarm.

You should also check your hood latch sensor. If there is any debris or buildup, you will need to clean it. This buildup makes it appear that someone is trying to break into your car and open the hood. This will set off the car alarm system.

Also, if the latch sensor is damaged it will set off the alarm as well.

Still having alarm problems?

If after you have checked these potential problems and made sure everything is ok, you are still having alarm problems you need to bring your car to a professional. It is a good idea to have them run your car’s diagnostics to make sure that no other sensors are misfiring.


Car alarms are extremely useful tools. They help prevent theft by alerting us to intruders. And they also can potentially let us know when our cars may be having battery or sensor issues.

So, while a constant or random alarm may be annoying, it is trying to tell you something. It is worth the time and effort to find out why your alarm is constantly going off.

It may not only prevent your car from being stolen, but it may also save you from a dead battery and being stranded somewhere.

Mike Cross
Life is too short to drive with stock audio

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