Car Alarm Keeps Going off for No Reason: How to Fix the Problem

Car alarms must be among the most useful contrivances ever made. They make sure your car is safe by driving away potential car burglars and can even warn you if there is something wrong with your vehicle. Not to mention that car alarms are exceptionally affordable for most car models. Most people wouldn’t even consider driving a car that doesn’t have one installed nowadays. Except when the car alarm keeps going off for no reason, that is.

A malfunctioning alarm can drive the owner of the car to the bend. A car alarm sounding without an apparent reason can be not only frustrating but also embarrassing for the person. Think about your car’s siren blaring in a busy public place and countless onlookers watching you fidgeting with your keys, not knowing how to stop the obnoxious noise. Not to mention all the unsuspecting neighbors who wake from their restful slumbers because of the whining of your car’s security alarm.

Not knowing what causes the glitch is a problem in itself, but not being able to stop it when it happens is quite another one. That rings especially true if there are other people who have to put up with your car’s siren. Here I will explain how car security systems work and what usually sets them off, and I will offer several viable solutions for blasting car alarms.

What to do when your car alarm keeps going off.

What Causes a Car Alarm to Go Off?

A car alarm is designed to keep your car safe. Whenever it detects suspicious activity in the vehicle, the alarm is supposed to sound. The circumstances that may trigger it vary anywhere from low car battery alerts to attempted car burglaries.

Every modern car has shock sensors that react to forceful impacts on the car. That is what makes the alarm go off in case of a car crash. Also, the switches set up on the vehicle’s doors, hood, and trunk deter thieves from picking your car’s locks. When something triggers those switches, the alarm will instantly notify the owner about the felony.

But sometimes, it seems your car alarm keeps going off for no reason. In some cases, your car’s security system may misinterpret extremely loud noises or particularly strong winds as physical impacts to the vehicle and set the horn off as a result. But if that happens repeatedly, it means there may be something amiss with your vehicle, and you should find the source of the problem.

The Usual Suspects for a Blaring Car Alarm

Although it may seem there is nothing that is causing your car alarm to rave, if it turns into a recurring issue, you may want to look into it. Some of the culprits for the roaring car security system could be:

  • A broken fob
  • A dead car battery
  • Rusty battery terminals
  • Dirty latches
  • A malfunctioning sensor

A Broken Key Fob

The most common cause of an unexpected alarm alert is a faulty key fob. Key fobs are convenient because they allow you to lock and unlock your vehicle with a press of a button.

But when the batteries in the fob are running low, it may start to behave strangely and send random signals to your car. As a result, the alarm will sound to alert you of a possible intrusion or another suspicious activity.

If replacing the old batteries with new ones doesn’t do the trick, you may need to consider consulting a professional or replacing the fob altogether.

A Low or Dead Car Battery

A car battery that is low on energy or is almost entirely out of juice can also trigger your car alarm. That is because security systems can detect the malfunctioning of some parts of your vehicle and warn you about it by sounding off. That applies to the car battery as well — when you try to start your car on a low battery, the alarm will go off and draw your attention to the issue at hand.

Use a voltmeter to check whether your car battery is empty. Anything under 12.6 volts is a cause for concern and suggests you should replace the battery soon. As a temporary fix, you can use a set of jumper cables to recharge the battery with another battery. Jumpstarting your car will allow you to drive it with the existing battery for a while longer. But keep in mind that you will inevitably have to get a new one.

Rusty or Corroded Battery Terminals

The battery in your car can trigger the alarm in yet another way. Sometimes, the terminals on the car battery become rusty due to infrequent maintenance and the prolonged exposure to damp weather, grease, and dirt. When the terminals become corroded, they are unable to transmit the proper amounts of energy to the rest of the vehicle. The car’s security system interprets that as low battery power and sets the alarm off.

Alternatively, the battery terminals may become damaged or worn out. That can also result in poor power transmission, and send the alarm flaring.

There Is Dirt Build-Up on the Hood Latch

Excessively dirty hood latches can also trigger false car alarms because the system will mistake the dirt build-up for an intrusion. The hood of your car is consistently exposed to weather conditions, dust, dirt, road debris, and car grease. So it comes as no surprise that a lot of dirt gathers there.

To prevent dirt from causing damage to the parts of your vehicle, including the hood latch, is to maintain it regularly. A simple mix of strong detergent and water combined with a good scrubbing brush will do the trick.

Broken Latch Sensor Connections

If gunk build-up is not the cause, corrupted latch sensor connections may be to blame for unexpected alarms. When the latch sensors do not function properly, the security system assumes that the doors, the hood, or the trunk have been opened forcibly or the car has been broken into.

Broken latch connections can also trigger random incorrect indications to light up. For instance, you may observe that the doors on the car are open when they are not. Also, it may show that there is a problem with your airbags when they are perfectly fine.

If something similar happens to you, you may try disconnecting and reconnecting the sensor. If that doesn’t help solve the problem, you’ll have no option but to consult an expert.

How to Fix a Car Alarm That Keeps Going off for No Reason

Finding the root of the problem is definitely important. But what should you do when you are experiencing this annoying alarm issue and need to stop it as soon as possible? Your car alarm could sound when you least expect it. Keep one of the tips below in mind to avoid being caught off guard when it does happen to you.

Here’s what you could do in the situation when the car alarm keeps going off for no reason:

  • Use your keys or your key fob to stop it
  • Check the panic button
  • Consult the owner’s manual
  • Remove the alarm fuse from the fuse box

Use Your Car Keys or Key Fob

The first and the simplest thing to do is to insert your key in the car door lock. Many security systems will disengage once the key is in the lock as it supposedly identifies the owner. That works best on the driver’s side door, but with some car models, it may work on the passenger’s door as well. Alternatively, you may need to lock and unlock the car either with your key or by pushing the buttons on the key fob.

Check the Panic Button

Make sure that you haven’t accidentally pressed the panic button that some key fobs have. It is usually yellow or orange and, once it is pushed, the lights flash and the siren sounds. Press it once to check if that is the matter. If that doesn’t work, start your car and begin driving it to see if that causes the alarm to become silent.

Browse the Owner’s Manual

It may not be applicable in all situations, but if you can, do read through your car’s owner’s manual. It may contain valuable information on the vehicle’s alarm system and tips on how to disengage it quickly. The best thing to do is to read it upfront. That way, you’ll be all set if your car alarm keeps going off for no reason.

Take out the Appropriate Fuse

Use your owner’s manual to check which fuse powers your alarm system, if your car has more than one. Use plastic tweezers or needle-nose pliers to remove the fuse from the fuse box. If you take out the right one, the alarm will shut down immediately. It should not start again after you return the fuse in its place. In case it does, it means the alarm system is broken, and you need to have a professional take a look at it.

Final Thoughts

A roaring car alarm is enough to set anyone’s teeth on edge. However, if your car alarm keeps on going off for no reason repeatedly and is giving you a hard time when you try to turn it off, some of my tips above should do the trick.

If all else fails, you will inevitably have to visit your car mechanic. It may cost you a bit to repair a faulty alarm system, but the safety of your vehicle trumps it all.




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