How To Install a Car Alarm (Easy 5 Step Guide)

Are you looking for a simple way to install a car alarm?

​You've come to the right place!

In this guide, you'll learn:

  • What you need to know about installing a car alarm
  • Reasons why it's a good idea to install an alarm
  • The essential steps to installing a car alarm yourself

And much more!

How To Install a Car Alarm (Easy 5 Step Guide)

Installing a car alarm is a good idea if you live in areas where you are at risk of having items or even your whole vehicle stolen. 

Even if you live in a safe area, you might want to install a car alarm system for the function of remote start and locking/unlocking. 

Want some good reasons to install an aftermarket alarm system? Here are a few:

  • Protect your valuable possessions
  • Keep your vehicle safe
  • Lower the cost insurance policy(possibly)
  • Know where your vehicle is located at all times

Alarm systems have tons of cool features that can give you extra access to your vehicle, so shop carefully before you purchase the best fit for your vehicle.

So, before you do install a car alarm, I recommend you read our guide on how to do it right.

What You Need To Know About Installing a Car Alarm

Most newer model-year vehicles have some sort of alarm system that helps to repel car thieves; whether it's a full out GPS tracking system, or just a car door alarm will depend on the quality of the vehicle.

Customers who want a quality security system will surely be driving a luxury vehicle. 

But just because you drive a cheaper car, doesn't mean you have to skimp on personal security and the security of your possessions. 

Installing a car alarm requires a mixture of electrical smarts and delicate hands for removing plastic trim panels. 

Want to do the installation yourself? We say go for it; it won't be easy if you are a beginner, but it will be worth it to learn more about the electronics system in your vehicle.

Read More >> ​How Do You Install A GPS Tracker In Your Car?

Supplies You'll Need to Install A Car Alarm

Here are some of the essential supplies you’ll need for installing an alarm inside a vehicle:

  • Multimeter
  • Electric repair kit (wire strippers, soldering iron, heat-shrink tubing, crimping tool)
  • Electrical Tape
  • Power Drill
  • Power wire
  • Zip ties
  • Pick tools/plastic trim remover tools

The internet is an invaluable resource when performing automotive repairs.

Not only can you search Youtube videos like the one posted above for solutions, but you can also purchase parts from auto retailers on sites like Amazon, and have them delivered to your doorstep within just a couple of days. 

Read More >> How Do You Install A Heads Up Display In Your Car?

How To Install a Car Alarm (5 Step Guide)

  1. Choose your system
  2. Prep the system's wiring harness
  3. Remove vehicle paneling
  4. Install wiring harness
  5. Test function and replace the paneling

Step 1: Choose Your System

You must first prioritize what you want your alarm system to do based on price, vehicle model, etc. Some common functions of a car alarm system include:

GPS tracking

Want to know where your vehicle is at all times? A GPS tracking device hard-wired into the vehicle will give you the confidence that if your vehicle is stolen you will be able to find it again. You may have to purchase a GPS tracker separate from the actual alarm system, but you won't regret it. 

Simply install the tracker, sync it up with your smartphone, and you're good to go. 

Keyless entry/remote controls

The modern commodity of being able to push the unlock button is a feature most vehicle owners can't live without.

Shock sensors 

Your vehicle will be hard to steal if it has shock sensors. Most thieves hit the car doors before breaking into seeing if it will set off an alarm.

Horn/siren activation

Alarm systems usually come with a siren that is mounted inside the engine bay with self-tapping screws. If your alarm system of choice doesn't come with a siren it probably has wiring that goes to the vehicle's horn. 


Immobilizers protect your vehicle from being hot-wired or started without authorization. Immobilizers can also be activated when a level sensor is triggered to prevent your vehicle from being towed. 

Remote start system

Few things are more convenient than getting into a warm vehicle on a cold day. With a remote start system, you can forget about warming up your vehicle in the winter---it will warm up for you. 

Smartphone integration

Want all of these great security functions integrated with your cellular device? 

No problem. These features are becoming more digitally accessible by the day. Just search for something like "mobile car alarm" on Amazon, and you will find exactly what you need. Check out brands like Viper for a good idea of car security system quality.

Step 2: DIY Game Plan: Prepping the Wiring Harness

Each system will have a different installation process, but they will all be similar in the fact that you will have to do some electrical finagling.  

Acquire a service manual for your vehicle so you can see all of the wiring diagrams. 

What features of the alarm system are you going to be able to use? Which are compatible with your vehicle? These are questions you need to ask yourself before the install. 

Now is the time to figure out all the logistics. For features that you don't plan on using, you can cut the wires short or wind them up on the control unit to help you deal with less wiring. 

Some vehicles may need extra relays and resistors added into the system for proper function. If you are going to do the job yourself, you will save yourself a lot of time by buying everything you need beforehand.

There's nothing worse than having to drive your vehicle to the auto parts store with the inside half ripped apart.

Step 3: Remove necessary paneling

It can sometimes be difficult to know where to start when removing the paneling, and breaking off plastic fasteners is inconvenient when you try to unsuccessfully put them back on.

The best technique, if you have never removed a panel before, is to follow the instructions by the book.

Pick up a set of automotive plastic trim puller tools that make the job a whole lot easier, and they also help you avoid damaging the trim on your vehicle because they are made of plastic.

You're going to have to remove the trim panel underneath and around the steering wheel, the kick panels, and possibly the door panels. 

The electrical components of the aftermarket alarm system will be incorporated into the ignition harness, at the dash, or inside the kick panel, so finding close locations for all parts of the alarm system to be mounted in the name of the game.

The idea is to make your alarm system install look like it is part of the vehicle's stock appearance. Any sign of alarm installation will make it easier for an experienced car thief to disable the system upon entering. 

Read More >> How Do You Install A Remote Car Starter In Your Car?

Step 4: Correctly Install Wiring Harness

Use the video above to help you get a good idea of how you should install and fasten all of the wiring and other electrical components into the wiring harness.

Removing the negative battery terminal is always a good idea when doing most electrical work on a vehicle--that is unless you're testing wires. 

There are a few different ways you can join wires together. The recommended technique for luxury vehicles is either by using a soldering gun and heat tubing, or a crush connector. 

Whichever way you do it, make sure that the wires aren't going to come apart. 

Buy an electrical repair kit from your local auto parts store for good parts like crush connectors and shrink tubing that will help you do a professional job. 

Check out the video above for a good example of joining two electrical wires together. 

And let's face it, installing a car alarm isn't exactly the most simple installation. If you are doubting yourself, you may want to give your local auto shop a call, and ask for an estimate on getting your alarm system professionally installed.

Step 5: Test Function and Replace Paneling 

Don't start replacing the trim panels quite yet! Once you have all of the alarm features installed and are feeling confident, it's time to test out the system. 

The best way to do this is by going by the user's manual of the alarm system itself. Follow the instructions, and go through all the functions of the system to make sure you have performed the job properly. 

After you have gone through all of the functions and confirmed the proper function, you can then start installing the panels and cleaning everything up. 

There you have it! Your old vintage vehicle or stock option vehicle is now secured from evil people looking to bust into your life's possessions. 

One last thought: if you leave valuable possessions in a clear view inside your vehicle, it doesn't matter how good your alarm system is; thieves will still bash your windows, grab your possessions, and be gone by the time anyone notices the alarm. Be cautious when traveling!

Other Valuable Resources on Installing a Car Alarm

It's going to work out just fine regardless of which panorama you make for your car alarm system installation. Check out other alarm systems like Avital, Spy, Python, and Pyle. And remember, if you want to install an alarm system in your vehicle but don't know where to start you can always call your local auto parts store or car dealership to help point you in the right direction.

Opt For High Quality

High-end alarm systems will give you high-technology security and access to your car.

Chances are if your vehicle is equipped with a high-end alarm system you will have access to it through a key fob and be able to perform tasks straight from your smartphone.

Your high-end system will be super equipped with all the quality bells and whistles, like a remote starter, GPS tracking device, camera surveillance, keyless entry, and more that will do the job a lot better than a cheap system.

Low-end alarm systems that have door and shock sensors with a siren might do the trick for getting rid of car thieves, but here at Proper Mechanic, we think if you are going to modify your vehicle that it should be a quality upgrade.

Buying a cheap alarm system that isn't going to work in the worst of moments is just a waste of time. 

And remember, some car thieves are good at what they do; protect your possessions by using the best alarm system you can get.

Read More >> How Do You Restore Car Headlights On Your Own?

Did you know: After car alarms became standard on vehicles in the 80s and 90s, they actually became less effective because they were triggered so frequently people ignored them. Now, however, manufacturers opt for silent immobilizers.

How Much Will A Professional Installation Cost?

Preventing break-ins is the end goal when installing your alarm system, right? And you want your car alarm system to function at its top potential to evoke theft.

The easy way to get exactly what you want is to hire a professional to handle the job for you. Chances are if you have never installed a car alarm before you are going to lose a lot of time with the learning curve.

Save time by letting a professional equip you with the right setup for your specific vehicle.

Any car dealership is going to charge you at least two service hours for installing an aftermarket alarm system.

You could be looking at more like 3 or 4 hours of charged labor depending on the circumstances. And seeing as most dealerships charge anywhere from $50-100 for one hour of service you can see how the price will quickly add up.

If you are looking to install a basic system that sounds an alarm when someone opens the door, then you aren't going to be looking at too high of a price for an install.

The professional installation of a basic car alarm won't be hard for someone who knows what they are doing, so it's worth the extra money for the peace of mind that your car won't be damaged in the process.

About Your Mechanic

About Ryan Nichols

Ryan here! My pro mechanic career began as a technician for Mercedes-Benz. After two years of that great experience, I went out on my own in both the automotive and construction fields. I've since pulled my share of salvage yard parts and fixed more vehicles than I can count.

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