Installing a Car Alarm

So you have taken the step to protect your vehicle. Good choice. Car alarms can provide years of safety, convince and piece of mind. Now the question is, how is this installed. What seems like a hard task is actually a little easier than once though. It is all about planning, information and careful execution. Yes, you will need to do a little research to make your installation easier. The more information and reference diagrams, the better. You will need to learn how to test the polarity of a wire using a digital multimeter. Lastly, you will need your basic tools to remove some vehicle panels to access the vehicle wiring.

Gathering Information and Reference Material

Information is the backbone of your soon to be successful installation. You should gather documents with vehicle specific wiring colors, locations and polarities. These charts are available in a multitude of places, generally free of charge. You will want to identify how many, if any, relays your vehicle will need. Depending on the model, it could also require diodes and/or resistors. You will want to be sure if any of these additional pieces are needed, you have a diagram available at the time of installation to keep your work progress flowing.

Planning the Car Alarm Install

Your plan will be the difference between a finished product and a job left for next summer. A few minutes of planning and prepping will yield at least an hour and a half less install time. It’s not fun, let get it finished! Begin by studying your vehicle specific diagram side by side with your car alarm installation manual. Identify which features you plan to use on the alarm. Ex…keyless entry, starter disable, trunk pop, dome light supervision etc.

Prepping the Alarm Unit

Once you identify which items you will install along with the alarm, eliminate the unused wires to prevent clutter. Generally, this is as simply as pressing a paper clip down on the metal contacts, with it unplugged of course. It is common practice to twist the wires of a same plug together then secure them to each other with electrical tape. Do not wrap the entire bundle, as different wires go to different locations. Once you finish wrapping all the harnesses tape them to each other to create one large pigtail containing all of the used wires. This keeps the wires together, secure and free from frays and obstruction. You will now want to identify the locations of the wires which you will connect to on your vehicle. Common areas are the drivers kick panel, ignition harness and body control modules. Take your harness of wires on the alarm which you just organized together, and split it down once more into vehicle locations. Group kick panel wires with each other, ignition harness wires with each other and so on. Tape these wires together in their bundles to create individual wiring bundles.

Checking the Vehicle

You will need to inspect your vehicle to be sure of a few things previous to beginning the installation process. Begin by checking your door triggers. Be sure when EACH door is opened on the vehicle, the dome light and/or dash door ajar indicator is light. If it is not, you may have a faulty door trigger which will cause the alarm to ignore that door. Next, check your vehicle and identify which tools are needed to remove the necessary panels. You will once again refer to your vehicle wiring diagram to find the locations of the wires where the panels will be removed. Once done, you are ready to begin the installation.

Execution

Removing the Panels

We will begin by saying tools! The right tools are the difference between cut hands or no sweat. You will find our entire list here. We suggest you seriously consider the specialty items, as they will be handy in other wiring projects in your future. You will want to begin be removing the panels where your wires are located. Be sure to notate where all clips and screws go.

Wiring the Car Alarm Unit

Once the panels are removed, you will want to locate a good spot to mount the module. The harder to see the better. This will make it much more difficult for a would be thief. You will generally tie strap the module to a support brace or stiff wiring harness. Next, run your valet switch, LED light and external antenna, if equipped. At this time, everything which will be plugged into the unit should be. Begin by wiring any necessary relays first, if any are necessary. Getting this out of the way now will save you from a rats nest of wires. After the relays are wired, begin connecting your wires to the proper locations. You may want to read our article on testing wires polarity before making any connections. You should always test wires before you make a connection. Connecting the wires can be done in a number of fashions. You can splice the wires and tape them using electrical tape. You can solder then tape or heat shrink. You can use t-tap connectors, although we personally do not recommend them. It is completely your preference. Just be sure the connection is solid and free of any tension. Once your connections are complete under the dash, you will need to install your siren.

Installing the Siren

Most car alarm units have a positive (+) siren output. The siren will have 2 wires, one positive (+) and one negative (-). Connect the wire from the unit to the positive (+) wire on the siren. Put the other wire to ground. Before doing this, you must pass the wire through the firewall and mount the siren in the engine bay. Passing the wire through the firewall is a simple task. Some vehicles have plugs which are not used. You could pass the wire through this plug with a dab of silicone to keep any moisture out. If there is no available passage hole, you will need to drill a small hole. Drill the hole in an inconspicuous spot on the firewall, minding anything attached to the other side of where you are drilling. Pass the wire through this hole using a rubber garment boot or sealing it with silicone. Next you will want to fasten the siren to the vehicle. Locate a spot on the fire wall or equivalent where there is space enough to fit it in. You will want to use self tapers and securely fasten the siren to the vehicle. Be sure the siren opening is facing down to prevent water from gathering and to echo the sound off the floor. Now connect your alarm wires as described above.

Your installation should now be complete. Put the panels back on the vehicle and open your manual. There should be a section for testing your installation. Go through this process thoroughly. You will want to address any issues, if any immediately. If you are having problems, refer to our trouble shooting an install. If not, congratulations!