If you’ve ever experienced a car alarm that won’t stop going off, then you know how frustrating it can be. Car alarms can go off unexpectedly in the middle of the night, for no reason at all, and worse, while you’re driving down the road!
We get it, and we want to help you figure it out. That’s why we put together a complete guide to help guide you through everything you need to know to troubleshoot your issue permanently.
How a Car Alarm System Works
To assist with troubleshooting, it’s good to have a basic understanding of how these alarms work in the first place. There are multiple generations of car alarms, and they all have some or most of these features.
First, almost every car alarm has a connection to the car door and trunk sensors. This is beneficial, as if an assailant picks your lock or smashes out the window (to simply unlock the car).
Or simply opens the door or trunk by some other means, you want the alarm to let others around you know something is wrong.
By using your car key fob to unlock a car, the fob disables the alarm. But if the assailant unlocks your car without using a car key fob, it can set off the alarm.
This aligns with the situation when you lock the vehicle from outside, and someone inside the car unlocks the car and exits.
Another sensor alarm system used to trigger the alarm is shock sensors. Not every car is equipped with a shock sensor, but if your vehicle does, it helps deter some cars from theft. Shock sensors detect an impact on your vehicle.
This can be measured as someone runs to your car or when someone uses force to smash a window.
This is significant because on a traditional alarm system, they can smash the window and grab whatever they want, as long as they don’t open the door, and no alarm is triggered!
Shock sensors provide another layer of theft deterrent. They can also trigger the alarm if someone is in the process of picking the lock on your car. It’s nice to see the alarm go off before anyone even tries to get in!
When Your Car Alarm Is Going Off All the Time, why?
There are more than a few reasons your car alarm might go off too often. In the next section, we list seven reasons your alarm may be acting up.
#1. Dead Battery.
This may not make a lot of sense to you right now, but if our battery is low or dead, it can create a lot of strange issues with our vehicle. It would not be uncommon for a battery with a dead cell or other electrical issues to trip the car alarm.
If the alarm is going off and you notice your vehicle needing a jump start more often, or you notice any other abnormalities with the vehicle, you should check the battery.
#2. Key FOB Malfunction.
One of the most common issues with a car alarm that keeps going off is a malfunctioning key fob. The key fob is a manual way to trip the alarm system, If the key fob is malfunctioning, it will trip the car alarm when you don’t want it to.
If you think that the key fob may be the issue, try changing the key fob battery and see if the alarm starts going off. Some key fobs can be reset. Check your car manual or call the manufacturer, or consult the aftermarket car alarm manufacturer for reset directions if applicable.
#3. Blocked or Damaged Sensors.
Your car alarm includes a number of sensors that tell you if there is a problem. It is intuitive that if some of those sensors are not functioning properly that you may have a car alarm problem.
Most car alarm problems occur due to blocked or damaged door or trunk sensors.
#4. Wiring Problem.
Everything in car alarms uses electricity, and every electrical system uses wiring. When everything is functioning properly, there should not be any issues.
When electricity goes to the wrong place, it can be because of damaged wiring, crossed wires, etc. If your car alarm is experiencing faults, that may be an indication of a wiring issue.
Although wiring problems can be difficult to troubleshoot, it is usually quite easy to fix once the fault is determined!
#5. Over-Sensitive Sensors.
In addition to the trunk and door sensors, your vehicle may also use shock sensors to set off a car alarm. Many of these shock sensors have a variety of sensitivities to alarm triggers, with the highest sensitivity being possible to trigger with a brush of a cat.
If you find that your shock sensors are too sensitive, you can adjust them yourself or take them to a dealer.
#6. Control Unit Failure.
Your vehicle’s alarm system is made up of sensors that report to an alarm control unit. Although rare (it is usually a sensor problem), it is possible for a control unit to fail.
After ruling out the sensors and being assured that voltage is present at the control unit, the control unit is more than likely your problem.
#7. Bad Installation.
If you have just installed an aftermarket alarm system and the alarm is constantly going off, it may mean that something was not wired correctly.
There could simply be a crossed wire, an undetected sensor, or possibly the installation instructions were not followed correctly. It may be worth it to review the installation process, and/or bring it to where you bought it.
How to Turn Off Your Car’s Alarm without a Working Key Fob
You may want to fix the car alarm, but when the key fob is not working and you simply want it to stop, what are your options? Fortunately, you’re not stuck high and dry. Below, I provide you with four possible solutions.
The first two options are the easiest and don’t work in every case, but the last two will turn off your car alarm every single time.
#1. Start the Car!
When your car alarm works as intended, it should go off when you start the car. That’s because your car’s ignition system has an anti-theft device.
If your car sees that you’re the correct guy trying to start it, then there’s no need to be alerting thieves, right?
If you have an older vehicle, this may not work as expected. If the issue is due to the control unit, it may set off the alarm even after you start driving.
#2. Lock and unlock the car.
Sometimes this is all it takes to reset the alarm system and prevent the alarm from going off altogether! Lock the car and unlock the car, and many vehicle alarm systems will deactivate.
This is also not foolproof. If the issue is the control unit, this may not work. But, it will likely reset the system and get you some much-deserved peace.
#3. Remove the fuse.
If you have tried the first two options without shutting off the alarm, this is likely your best bet. The car alarm system runs through a fuse to protect the circuit. If you pull the fuse with a pair of needle-nose pliers, your car alarm will not have any power. No power = no alarm.
Even better, since you only pulled the fuse for the alarm circuit, everything else in your vehicle should work as intended. The only difference is that your vehicle does not have a car alarm because you cut power to that circuit.
Now it is up to you to determine if you should get it fixed, and for you to weigh the cost of those added layers of security to the belongings in your vehicle.
#4. Disconnect the battery.
Disconnecting the battery is another fail-proof way to cut power to the alarm. Disconnecting your battery removes the electricity from all the circuits in your vehicle. And that will definitely stop the alarm!
The only nuisance is that you have now disabled all of the systems of your vehicle. This may be problematic if you need to use your vehicle while you sort out the issue with the car alarm system.