Skip to content

How to Remove an Aftermarket Car Alarm System

This article is a collaborative effort, crafted and edited by a team of dedicated professionals.

Contributors: Muhammad Baballe Ahmad, Mehmet Cavas, Sudhir Chitnis, and Zhen-ya Liu.

✓ Verified & Tested Information

This guide will show you how to remove an aftermarket car alarm system.


Before removing the aftermarket car alarm system from your vehicle, you should make sure that you are prepared for the job. Gather any necessary tools, such as screwdrivers, pliers, wire strippers, etc. You should also take a few minutes to familiarize yourself with the car alarm system and its wiring before you begin to take it apart. This will make the process easier and help you to avoid damaging the system and wiring in the process.

Locate the alarm system

Before attempting to remove an aftermarket car alarm system, it is important that you first locate the system. Many aftermarket systems are installed in hard-to-reach places such as beneath the dashboard or in the trunk or behind panels within the car. If the system is integrated with your vehicle’s factory alarm, then it will be located near any other access points such as power door locks and power windows. Most aftermarket systems come with instructions on how to locate them, so consult these instructions before beginning. It is important to remember that some systems may require special tools or wiring harnesses that may not be included with the basic installation kit for the system. Be sure to have all of these items available and accessible prior to beginning removal of the system.

Disconnect the car battery

When removing an aftermarket car alarm system from your vehicle, it is important to disconnect the power source before beginning the process. The power source or energy source is usually a car battery and should be deactivated before beginning, as this will ensure there is no danger of damaging any of the components of the existing alarm system.

It is important to know how to safely and correctly disconnect a car battery before you attempt to remove an aftermarket car alarm system. You can start by identifying both terminals – one with a positive (red) symbol and one with a negative (black) symbol on them. You can then use the appropriate tools such as both adjustable and non-adjustable wrenches to loosen and remove each terminal from the battery itself. Before finally removing each terminal, make sure all loose wires are secured in order to prevent from electrical malfunctions occurring during removal. Finally, you should move away all metal parts from around the terminals completely for safety reasons and for convenience when installing replacement parts since metal objects are highly conductive during installation processes.

Gather the necessary tools

Before attempting to remove an aftermarket car alarm system, it is important to gather the necessary tools. To get started, you’ll need a Phillips screwdriver, a multimeter (for testing wires), a 9 volt battery (as an energy source), and a wire cutter/stripper tool. You will also need two sets of jumper wires; this will help you disconnect power from the operating system by connecting two separate batteries or two sources of 12 volts DC. In addition to the tools mentioned above, it may be necessary to locate an owner’s manual for your vehicle in order to locate specific areas such as mounting screws, wiring diagram information and diagnostic codes that can provide useful information when troubleshooting the system. Once you have gathered all the necessary tools, you can proceed with removing the car alarm system from your vehicle.

Disconnect the Wiring

Removing an aftermarket car alarm system requires you to disconnect the wiring from the alarm system in order to prevent any damage to the vehicle. You’ll need to be sure to identify the correct wiring connections in order to ensure an efficient and safe removal process. After disconnecting the wiring, you’ll be able to access the main components of the system, allowing you to take the necessary steps to completely remove the system.

Locate the main wiring harness

The main wiring harness connects the car alarm system to your vehicle’s electrical system. In order to disconnect and remove the aftermarket car alarm system it is important to locate this crucial connection point. Depending on the make and model of your vehicle, this main wiring harness can typically be found in one of two places: either near the fuse box beneath the dashboard or at the back of your vehicle near other aftermarket connections. Once you have located the wiring harness it will be necessary to physically disconnect each wire from its corresponding terminal or connecter within the main wiring harness itself. Use caution when unplugging these wires and take care to label them appropriately so that you can correctly reconnect them if desired.

Unplug the wiring harness

Once all of the screws securing the head unit or internal wiring connector have been removed, you will need to unplug the wiring harness from the car’s electrical systems. Depending on your specific aftermarket alarm system and vehicle make/model, this may be done by removing a fuse located underneath the vehicle’s dash. Before opening up any interior components, consult your owner’s manual to locate and identify any selectable fuses that are associated with the alarm system installed in your vehicle.

Next, check for any exposed wirings connected to ignition cylinders or starter motors that are related to the system. It is recommended that any shattered wires should be disconnected using a combination of pliers and wire cutters. To ensure total disconnection without causing harm to your car battery or engine components, ground any wires left exposed with a screwdriver prior to cutting them off completely. This will help make sure there is no electrical current running through them when you are ready to go back into what was working earlier on installation.

Remove the alarm system

The safest and most efficient way to remove an aftermarket car alarm system is to disconnect the wiring. To do this, you will need to locate the alarm control module-typically located in the engine bay or dashboard-and remove it from its mounting point. You may also need to remove any remote start switches and dash components such as LED status lights.

Once all of the necessary components have been removed, you can begin disconnecting the wiring. Unplug any relays or amplifiers that may be attached to your alarm system and disconnect the positive wire for your auxiliary battery or power source if applicable. Next, locate your alarm’s main power wire, which will typically be a thicker gauge wire with a red insulation coating that runs from your main battery to the alarm control module. Cut this wire with a suitable pair of scissors and then use electrical tape to insulate the ends of each portion of wire so they do not short out against each other or metal components inside your vehicle.

Your last step is going to be removing any antennae, which typically are mounted on an exterior part of the vehicle, such as on a spoiler or wheel well. Cut away any velcro if needed, unplug it from its corresponding connector and then ensure all wiring has been safely bundled up and secured away so it cannot cause any further damage as you move forward with restoring a factory setup in place of your old aftermarket car alarm system.

Remove the Parts

When removing an aftermarket car alarm system, the process begins by removing the main components of the system. This will involve disconnecting the main panel as well as removing any sensors and wiring that was connected to it. Make sure to keep these parts organized, as they will need to be reinstalled when you are done. Once these pieces are disconnected, the next step is to remove the other parts of the system.

Remove the siren

The siren portion of an aftermarket car alarm system is usually relatively easy to remove. It should be visible once you pop the hood and should have a relay connected to it. Disconnect the relay and then unscrew any bolts or clips that may be holding the siren in place. Once removed, store it in a safe place where it will not be damaged. Be mindful that the wires attached to the unit can still cause damage if you forget about them and accidentally shove them somewhere when installing your replacement alarms system. Ensure all cables are carefully disconnected before attempting to remove the siren from your vehicle.

Remove the sensors

Once you have disconnected the power, grounding and shocks wires of the aftermarket car alarm system, the next step is to remove the sensors. Most aftermarket car alarms come with shock sensors that detect unwanted vibrations or shaking of your car. These are typically mounted next to your car’s rear suspension with screws or adhesive strips. You’ll need to remove these first before proceeding with your removal process.

To begin, use a screwdriver or nut driver to loosen and remove each screw from its corresponding sensor location on your vehicle. Carefully wiggle each sensor out to avoid damaging any wiring inside the holes they were originally attached to. Once you’ve removed them all, set them aside and begin unplugging each sensor’s wiring directly from the control unit itself. It’s important that you label these sensors with their designated location numbers so that you’ll be able to install them back in their original places when it is time for a new alarm system installation.

Remove the control module

Before you can completely remove an aftermarket car alarm system, the control module needs to be located and disconnected. The control module is the heart of most auto alarm systems, sending and receiving signals that monitor the security of your car. It is usually mounted in a hidden location: under the dashboard, in the trunk, or behind a plastic trim panel.

Once you have located the control module, disconnect the power supply lead by pulling out its main connector carefully. This connector is usually a multipin plug that must be gently removed from its slot in order to avoid further damage to the system wiring or module itself. In some models, it may also be necessary to unplug one or more wires attached directly to particular circuit boards of the alarm system’s main housing unit. Other components such as sirens and remote controllers will then need to be unplugged or unscrewed before complete removal can occur. After all parts are disconnected and removed from their mounting positions, use tape or labels to identify their locations for possible future installation.

Reinstall the Original Parts

Removing an aftermarket car alarm system is not an easy task, but it can be accomplished. The first step in the process of removing an aftermarket car alarm system is to reinstall the original parts. This means that you must remove the alarm system and return the car to its original factory settings. This will ensure that the car continues to function correctly after the alarm system is removed.

Reinstall the original wiring

Once you’ve completed the task of removing the aftermarket car alarm, you must take the time to check the system and make sure the original wiring is replaced correctly into its respective places. If not done properly, this could cause problems with your car’s operation and your car’s electrical system.

The first step is to locate all connectors that were disconnected when you removed the alarm components. Carefully plug them back in, making sure they are clicked securely in place; check your owner’s manual or local dealership for advice on how these wires should be routed through their designated slots in order to ensure safety and efficiency. When reconnecting any bulbs or instruments to the alarm related wires, it is important to pay attention to which side is connected; otherwise, a blown fuse may result.

After completing all of these steps, disconnect and reconnect your battery cables so that everything can reset properly and be fully charged before starting up again. Your car should start with no outside assistance from an aftermarket system. Double-check all installed parts before closing anything up as this would help make sure nothing rattles or shakes around while driving as well as ensuring proper performance of all safety features in future use. Check the system one last time to ensure everything is functioning correctly.

Reinstall the siren

Before reattaching the original siren, make sure the wiring harness is properly secured and connected. Sometimes aftermarket alarm systems require special connectors to be purchased separately. If this is needed in your case, you will need to get the necessary connector and attach it. After securing the wiring harness, place the original siren back into its designated mounting bracket and tighten any screws that were removed during installation of the aftermarket system. Make sure all connections are secure and then proceed with reattaching any wires that were previously disconnected when installing the aftermarket alarm system; this includes power, ground and other previous disconnected wires. Finally, use a multimeter to check that there are no open electrical circuits before placing everything back together again.

Reinstall the sensors

Before replacing the cars original parts, it is important to test the alarm system to make sure everything is working properly. Once you have tested the alarm and are satisfied with its functionality, it is time to reinstall the original parts. Begin by inspecting all of the parts. If they are dirty, such as a worn seat belt buckle or sensors that need dusting, you can use a mild detergent and water solution to clean them.

Next, you will need to reinstall the car’s sensors including any motion sensors or door sensor s that were removed when installing the aftermarket system. Some sensors install with only two screws or bolts and others may require more complex assembly. Make sure that you reinstall all of your connectors in their original locations before moving onto your switches and relays on your car’s doors and trunk lid. Depending on your car model, these connections may be different for each vehicle so make sure to check before installing them incorrectly which could cause issues with your alarm system’s performance later on. It’s important to ensure that these sensors are reattached firmly as loose connections can cause alarms not to go off when they should be activated in an emergency situation.

Test the System

When removing an aftermarket car alarm system, it is important to test the system before making any modifications. This will help ensure that all of the components are working properly and will help identify any issues that may need to be addressed before making changes. Testing the system should be done by following the manufacturer’s instructions or consulting a professional. This may include turning on and off various components, activating and deactivating the alarm via the control panel, and ensuring the lights and siren are functioning.

Reconnect the car battery

Once you have disconnected the wiring harness, you are ready to reconnect the car battery. Before connecting the battery, make sure that all of the wiring is secured properly and all functions are in an “off” or “disarmed” position. This prevents any accidental triggering which may cause further damage to your aftermarket car alarm system. Once all of the wiring and systems are positioned properly, it’s time to reconnect the car battery.

First, remove the negative terminal from car battery using a socket wrench. Then, reattach it making sure it is tight before proceeding to attach the positive terminal in a similar manner using a socket wrench. Once both terminals are secure, replace any plastic insulating covers over them to ensure that no material or moisture can come into contact with them or your cars frame or body for possible short circuits and sparks. Finally, turn on your ignition switch and start your engine – If everything has reconnected correctly your vehicle should start normally with out any complications

Test the car alarm system

Before you begin the process of removing an aftermarket car alarm system, it is important to check the batteries and test the system to make sure it is functioning properly. Begin by checking that all components of the system are in working order and connected correctly. This includes the horn, siren, shock sensor, motion sensor and unlocking mechanism. If any of these components are disconnected or not working correctly, troubleshoot those issues first before disabling the car alarm.

Next, activate each feature of the system individually and make sure they function as they should. When testing door locks, be sure to use both remote entry systems and manual switches if applicable. Check the batteries to ensure that both entry systems lock and unlock all doors as expected, providing full access to all occupants when activated or locked out when inactive. Ensure that any automated windows roll down and up as commanded. Make sure all lights flash in response to a remote or switch actuation and all sensors are wired correctly as well.

Finally, test each response feature including horns honking at different volumes depending on multiple armed settings if available. Also check the batteries for maximum speed limits set by shock sensors and movement sensing functions for motion sensitivity controls. After completed this series of tests the alarm should be ready for removal from your vehicle’s electrical system.

Test all the electrical components

Testing all electrical components is a vital step in diagnosing and removing an aftermarket car alarm system. Start by inspecting the car battery and making sure that it is connected properly. You may need to test the battery voltage level with a multimeter to ensure the battery is functioning properly. Similarly, you will want to inspect all wiring connections and check for poor connections or loose wiring. Be sure to inspect splices, crimps and tape connections for any signs of damage or looseness.

Next, you should inspect each of the sensors included in the system such as motion sensors and door/trunk open/close sensors. Test these components by activating each one manually then verifying its response on the main unit. It’s also important to check for any corrosion or oxidation on the terminals of any electrical components; these are often caused by poor installation which can lead to weakened electrical signals or even complete failure of those components.

Once all electrical components have been tested, you can then connect them in the proper order as indicated by their documentation (or manufacturer’s website) before reconnecting the car alarm main unit itself according to its own documentation or manufacturer’s website directions. After verifying that all alerts are working properly, it is recommended that you carefully inspect your handiwork before powering up your car again; if there is any doubt about whether everything was connected as it should be, contact a professional technician who can be dispatched on-site for further assistance in properly diagnosing and removing an aftermarket car alarm system from your vehicle.

How to Remove an Aftermarket Car Alarm SystemCheckout this video:

Share this Article