Auto improvement: how to install a car alarm

Prevent the theft of your belongings or your car itself by installing your own car alarm system with these simple tips.

Why take your car to a professional to get an alarm installed, when you can do it yourself? It's easy enough if you know how. You'll need scissors, a knife, soldering gun, soldering material, crimps, drill, screw bit and screws, test light, tie wrap, double-sided mounting tape and a voltage meter. Be sure and completely read the installation manual that comes with the product. Because there are so many different makes and models of cars, and because each model is different when it comes to locks and doors, you will need some assistance from the manufacturer's help line. There should be a phone number listed on the package where you can call to find out what type of locking system your car has. Also ask what color of wire to connect to in order to interface the locking characteristics of the alarm. Question the advisor on how to install the relay for the door lock feature and what color of wire to connect to for the starter disable feature. In addition, ask how to hook up the relay and find out how to set up the voltmeter to test the door lock wires on your particular car. One more thing they can help you with is finding out how to access the factory door triggers. Check the installation manual to help you decide where to place each component. If you'll be installing an alarm with a current or voltage-sensing feature, ask the technician what color of wire works the overhead light and how you can access it.

Choose a solid metal surface under the hood where you'll attach the siren. Point the horn of the siren down toward the ground so that moisture won't settle in it. Drill a hole through a rubber grommet in the firewall of the car and slide the siren's wire through the hole into the main compartment of the car. Connect the power wire for the alarm to the car battery. Feed the wire through the grommet and into the passenger compartment. Place a fuse on the power wire next to the battery, checking the manual for proper fuse size. Mount the shock sensor by following the description in the manual. Drill a hole in the dash for placement of the LED status indicator. Feed the LED wire through the hole and use the double-sided tape on the back of the LED and place it over the hole in the dashboard. Find the wires that work the power door locks. Connect the door lock relay to the lock/unlock wires and attach the alarm wire to the relay.

If the alarm has current sensing, follow the tips from the technical advisor, and find the wire that works the courtesy light. Connect the current-sensing line from the alarm to the courtesy light wire. Locate the factory door triggers if the alarm doesn't have current or voltage sensing. Connect the factory door trigger to the alarm. Locate the starter wire on the steering column, a few inches below the starter switch. Cut the line and connect the starter disable relay. Connect the starter disable wire from the alarm to the relay. Mount the valet switch under the dashboard. Connect all the wires to the proper inputs and outputs of the alarm module. Using the drill and screw bit, mount the module to a safe and sturdy surface under the dash. Use the tie wraps to secure the wires of the harness and place it back under the dash.

Arm the alarm and then give it a test run. When you arm the alarm, the doors should lock and after disarming the alarm, the doors should now unlock. Arm the alarm once again and open a door using a key. The alarm should sound. Disarm the alarm, shut the door and arm the alarm yet again. Hit or bump the car with some force. The alarm should sound again. After disarming and arming the alarm one more time, try to start the car. You should not be able to start the car. If the alarm does not work properly, check your wiring and connections and try again. Installing your own alarm system isn't necessarily easy, but it saves you a bundle and will work as great as if the professionals had installed it.