How to Reset a Car Alarm

A car alarm that is not working at all or not working properly can be extremely annoying to you and your neighbors. It may also put your vehicle at an increased risk for theft or vandalism. Almost all car manufactures today provide several anti-theft options on their vehicles, including alarms. Alarms have proven to be an effective means of deterring potential thieves and vandals. While this is good news for owners of vehicles with alarms, these alarms, like other electrical components, can go bad.

The following steps will help guide you on how to reset your factory car alarm. While some of these tips may apply to aftermarket car alarms, it’s best to consult a manual if you are experiencing problems with your aftermarket alarm.

  • Note: Do not attempt any repairs you do not feel comfortable completing on your own. Because the alarm system draws power from the battery, you should exercise extreme caution when attempting any repairs.

Method 1 of 5: Resetting the alarm remote

It is possible that the key fob or alarm remote has failed and is not sending a proper signal to your vehicle’s alarm system. When this happens, your vehicle’s alarm may inadvertently end up going off without you wanting it to.

Step 1: Consult your manual. On older vehicles, the owner’s manual may provide a way to reset the key fob or alarm remote.

Most procedures will vary from car to car, but you can try removing and replacing the fob battery.

Step 2: Use a code reader. On newer vehicles, the key fob or alarm remote may need to be reset with a code reader/scanner.

Your owner’s manual may tell you how to complete this reset, though you may still want to consult a mechanic before attempting it.

Method 2 of 5: Resetting the alarm

Some of the more common alarm resets involve less-complicated techniques that can be completed in a matter of minutes.

Step 1: Unlock the car. Sometimes an alarm will deactivate when you try manually locking and unlocking the car.

When the vehicle notices that the key has been inserted into the lock, the alarm may shut off.

Step 2: Start the car. You may also try turning the car on to reset the alarm.

Step 3: Use key to lock and unlock. Try inserting your key into the door lock and turning the key to the locked position and then turning the key into the unlock position twice.

This may temporarily disable the vehicle’s alarm while you drive.

Step 4: Hold key in unlock position. You can also try holding the key in the unlock position for two seconds.

Method 3 of 5: Reset the battery

Resetting the alarm by unplugging your vehicle’s battery can be dangerous so you should use caution when attempting this method.

Step 1: Find your battery. Open your vehicle’s hood and locate the battery.

wrench being used to remove the negative terminal wire

Step 2: Remove the negative terminal wire. Use a wrench to loosen the nut of the negative terminal and remove the wire from the battery.

Step 3: Reattach the wire. After about a minute, reattach the wire.

This should reset all of your electrical systems including those that power the alarm.

  • Note: Disconnecting the battery will also cause your radio to forget presets. Be sure to write them down before removing the battery’s wire.

Method 4 of 5: Replacing the fuse

You may also want to try replacing the fuse that is associated with your vehicle’s alarm.

Step 1: Locate the fuse box. This is typically located under the left side of the steering wheel.

Step 2: Remove the corresponding fuse. Consult your manual to determine which fuse is associated with your car alarm.

replacing the fuse

Step 3: Replace the fuse. Replace it with a fuse rated for the same amperage.

Method 5 of 5: Disabling the alarm

If your alarm is causing a constant distraction, going off often and spontaneously, you may want to disable the alarm completely. Be mindful however, that if you disable the alarm, your vehicle will have one less safety feature. You should consult a mechanic before deciding to completely disable your alarm.

  • Note: Be aware that because some alarm systems work in conjunction with your vehicle’s ignition, meaning that if you tamper with the alarm, your vehicle may not start.

Step 1: Consult your vehicle’s owner manual. To find the correct wires to disconnect, you should consult your vehicle’s owner’s manual.

Resources specific to your car may also be available online.

  • Warning: You should be sure to disconnect the battery on your car before attempting to remove any other wires.

underside of alarm unit showing wire to be disconnected

Step 2: Remove the the wires connecting siren alarm control unit. By removing the wires connecting the siren and the alarm’s control unit, you can disable the alarm until it can be fixed permanently.

While faulty car alarms can be very annoying, it is important make sure there are not deeper issues at work. While these DIY fixes may solve your problem, you should always consult a mechanic if the solution seems more complicated. If you need a fuse replaced or a new battery installed, have one of YourMechanic’s certified technicians come to your home or work to do the job for you.


Next Step

Schedule Electric Problems Inspection

The most popular service booked by readers of this article is Electric Problems Inspection. Once the problem has been diagnosed, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. YourMechanic’s technicians bring the dealership to you by performing this job at your home or office 7-days a week between 7AM-9PM. We currently cover over 2,000 cities and have 100k+ 5-star reviews... LEARN MORE

SEE PRICING & SCHEDULING

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Recent Electric Problems Inspection reviews

Excellent Rating

(606)

Rating Summary
564
16
6
5
15
564
16
6
5
15

Jesse

16 years of experience
10 reviews
Jesse
16 years of experience
Kia Optima - Electric Problems - Port Orange, Florida
Jesse was great. Good communication on appointment timing. He is a fair and honest guy. I will recommend him to my friends.
Toyota Cressida - Electric Problems - Daytona Beach, Florida
I am pleased with my experience with Jesse. He did a thorough inspection to try to find what caused my car not to start. He explained what he was checking, along the way, and after every attempt to start the car. He also explained what was needed to, hopefully, get the car up and running. I would use Jesse if ever I have similar problems in the future.

Nicholas

11 years of experience
470 reviews
Nicholas
11 years of experience
Mazda CX-9 - Electric Problems - Morrisville, North Carolina
Super convenient. Mechanic showed up right on time. Fortunately, our issue was easily resolved with minimal hassle.
Jeep Wrangler - Electric Problems - Apex, North Carolina
Awesome mechanic. Honest and kept me in the loop. Highly recommend this company and Nicholas. -PL

JOHNNY

33 years of experience
96 reviews
JOHNNY
33 years of experience
Ford Edge - Electric Problems - Citrus Heights, California
Johnny was on time, honest, professional and very informative. Best experience that I've had in regards to mechanical work.
Honda Accord - Electric Problems - Roseville, California
Johnny was great he saved my family money very nice very respectful one of the best mechanic I have ever met and seen I will pick him for all future needs

Andrian

32 years of experience
184 reviews
Andrian
32 years of experience
Mercedes-Benz S430 - Electric Problems - Fort Lauderdale, Florida
Andrian was an excellent mechanic. He explained the problem to me in detail which was extremely helpful and he resolved the problem with professionalism and great attention to detail. I will definitely call to book another appointment with him if my Mercedes has any more issues in the future. I highly recommend him. Thanks!
Mercedes-Benz E320 - Electric Problems - Pompano Beach, Florida
This guy is the real deal nit just as a mechanic but as a genuine human being. He goes above and beyond to ensure that you understand what's happening with your vehicle.

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

Related articles

What to Do if Your Car Has Been Stolen
Many Many people have experienced that momentary jolt of fear after exiting a business and not seeing their vehicle. The first thought that comes to mind is that your vehicle has been stolen, but then you realize you parked it...
How to Decide Which Car Tracking System to Buy
There There are vehicles for every kind of purpose, whether it’s for personal use or business. Sometimes, you may need to know where a your vehicle is. It can be because: You can’t recall where your car is parked...
5 Essential Things to Know About Your Car's Anti-Theft Device
Your Your car’s anti-theft device is installed in an effort to help protect your investment from thieves. Most cars today include a variety of these devices and systems that not only protect the car, but also deter theft in the...

Related questions

Key stuck in ignition of 2001 Mercedes-Benz ML320

Hello. Most of the time, this is caused by a bad battery in the car. If the battery is low then this will occur. I typically start by checking the battery and doing a load test. If the battery is...

How do I set the security alarm?

The security alarm is a key safety feature that helps keep your car from being stolen. When someone enters your car without a key or the remote transmitter, the security alarm will activate, and the horn will honk and the...

HELP! wont start all of the sudden

In order to find out the reason for the crank no start you should first look at theft light on dash and when turn the key to on but not crank and see if theft light comes on and then...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com