Car alarms are a great way to add aftermarket security to popular vehicles. While most add audible (nuisance) alarms to the car, some give more disabling power making it impossible for someone to move the car without disabling the alarm.
The simplest way to disable an aftermarket alarm is by pressing the button on the remote keyfob.
What do you do if the keyfob is broken, the battery is out you misplaced the fob?
ProTip: This piece is purely informational. Don’t use the information to disable the alarm on a car that doesn’t belong to you. You could be prosecuted for attempted theft or tampering.
Find the Valet Switch and Disable the Alarm
The first alternative to disabling an aftermarket car alarm is finding the valet switch and disabling the alarm.
Since this is a critical security switch, most installations will hide it at a place only the car’s owner would know. We can’t direct you to where yours is if you don’t remember.
If it is your car and you remember the switch’s location, flip it to the off position, which will disable the alarm.
Disconnect the Wiring to the Alarm
If your system doesn’t have a valet switch, you can disable it by disconnecting the wiring powering it.
To do this, you have to know where the control module is located. Disabling it will be as easy as sniping out all the wires to the control module – or just those leading to the siren.
If the aftermarket car alarm is wired to disable the engine when engaged, you will have to get rid of all the spliced wiring and return your car’s ignition wiring to stock before you can move ahead.
Remove the Battery Terminals on Your Vehicle
Another desperate way to stop your aftermarket alarm from blaring is removing the negative power strap from your vehicle’s battery.
While your car won’t be going anywhere, it will definitely go silent. You can keep things this way until you find the alarm keyfob or identify the kill switch to disable the alarm.
ProTip: Some alarm systems have a backup battery that will keep an audible siren blaring for a while, even after cutting power.
Cut Wires to the Siren
Another destructive approach is cutting the wiring to the siren. Since the siren is critical for alerting the public of potential vandalism, installers hide them in tricky to access spots.
You will most probably need access to the hood or trunk to disable the siren. You will have to rewire it after you find the missing alarm control button.
What is the Best Way to Disable an Aftermarket Car Alarm System
So far, the most practical way to disable the alarm when you don’t have the key fob remote is:
- Flicking the valet or cutout switch off
- Disconnecting the battery terminal to cut off power to the system
Anything beyond this is damaging and will need repairs when it is time to reinstate the system.
Can I Turn Off My Neighbor’s Aftermarket Car Alarm?
No. There is no legal way to turn off someone else’s aftermarket alarm. Yes. The noisy alarms are annoying. However, you just have to wait for the car’s owner.
All the procedures to disable the alarm without a fob need you to have access to the car’s interior. If you don’t have the stock key to open the vehicle, you will have to break in. This is a crime if it isn’t your vehicle.
Do Aftermarket Car Alarms Help?
Aftermarket car alarm systems can, to some extent, make your car less attractive to thieves.
Nobody wants to be seen sitting in or rummaging through a wailing vehicle. They will run away as soon as the car starts making noise.
Moreover, some alarm systems have a cutoff circuit independent of the stock ignition system. This means the car won’t turn on until the aftermarket alarm is disabled or a cutout button is pressed at the right time.
This might make your vehicle harder to steal – unless the thief knows precisely where to go to disable the system.
Nonetheless, most modern vehicles have complex security features and immobilizers that make it hard to drive off without a programmed key. This and the fact that more and more people find audio alarms annoying has made aftermarket alarm systems less popular than they used to be.
Do Car Alarms Stop on Their Own?
My research has shown that most car alarm systems will keep blaring until the car’s battery runs out. If the system has a backup battery, it will keep sounding for even longer.
Some modules are programmed to stop the audible alarm after a couple of minutes – assuming the system isn’t triggered again.
Do Alarm LED Lights and Stickers Help?
Again, any warning that lets potential buglers or thieves think the car has an alarm system is a deterrent.
The warning LED light that comes with most systems must be prominently displayed to let people your vehicle has an armed aftermarket alarm system.
Alarm stickers will also pass the message across hence deterring all but the most desperate thieves.