Back in the 80s and 90s, it wasn’t too uncommon to hear the “chirp chirp” of someone arming the aftermarket alarm system in their car. And it was even more common here the annoying sonata of sounds that an aftermarket car alarm produces to the annoyance of everyone within one square of the car. But do those annoying noises, and that alarm-equipped car, really do any good in keeping that car from being stolen? Or is it just noise pollution?

What is the point of car alarms?

Aside from being annoying and noisy, the main point of having an alarm installed on your car is to deter any would-be thieves by bringing attention to the car. Not only is the alarm meant to prevent theft of the entire vehicle, but it’s also mainly to prevent theft of your belongings inside of it. And while you might still roll your eyes at the thought of a car alarm really doing any good, different car alarms do different things and will in turn have different levels of effectiveness.

OEM alarm systems

You might be wondering what the difference is between the OEM alarm and keyless entry system that your car came with versus an aftermarket alarm that’s manufactured by Viper or Clifford. The OEM alarm is typically a one-way alarm system that remotely locks and unlocks the doors, activates the remote start, initializes the starter/injector kill, and triggers the horn for the alarm. The reason it’s referred to as a “one-way” system is that the system can only be armed or disarmed and does not alert the owner of any mischief other than via the audible horn noise.

Aftermarket alarm systems

On the other hand, an aftermarket alarm system such as those made by Viper or Clifford (as well as many other manufacturers) has an array of functions when it comes to arming the car. These alarms systems not only go off when someone is trying to gain access to the car, but they can even warn people away with a proximity sensor and be triggered when the system detects the car being tilted, like if someone were to jack up the car to steal the wheels.

Since many of these alarm systems are “two-way” alarms, they typically consist of a pager remote key fob that will alert the owner if the alarm is activated. The pager will also notify the owner of what time the alarm was set off and if it was a false alarm or not. And while it might still seem like an alarm just causes noise, most alarm installers nowadays will install the system so that the car disables the signal to either the fuel pump or the car’s ignition system as an added layer of security.

Are aftermarket car alarms worth it?

While it’s easy to dismiss an aftermarket car alarm as just an expensive noisemaker — as some can cost around $200 to $300 – the most important aspect of getting one is the way that it’s installed. A good alarm installer will take their time hiding the wires and installing immobilizers for an added layer of security, while a lazy installer might just install the alarm in a haphazard way so that it only makes noise and unlocks the doors. In that case, it would be a waste.

If you’re planning on getting an aftermarket alarm installed on your car, just be sure to talk to the installer and know how they are planning to install the system and let them know of any custom settings you might want. While an alarm might not be able to completely save your car from being stolen, having an extra layer of security never hurts.