Immobilisers represent the first line of defence against car theft. Since 1998, many car manufacturers installed immobilisers in their vehicles as standard equipment. Fitting one is not an everyday task, and it does require some effort. Combining the knowledge of choosing the right kind with a few tips and some basic electrical work leads to a successful installation.
Level of Protection
An immobiliser disables the ignition, fuel, or starter system to render a vehicle immobile. However, as immobiliser bypass units exist to get around the security, disabling just one may not be enough to prevent car theft. Immobilisers can provide three varying levels of protection. A stage one immobiliser disables any one system. A popular choice is the ignition system, but it is also an obvious one. Choosing a less accessible system makes your vehicle slightly more secure. A stage two immobiliser can immobilise any two of the three systems in question. Lastly, a stage three immobiliser covers all systems. Immobiliser kits usually come with instructions on how to combine systems and attach wiring. Some kits even include a car alarm for extra security, but more components means more wiring and more work.
Ignition System Immobiliser
Immobilising the ignition system requires switching off the spark plugs in the ignition coil. Since the immobiliser units and the ignition coil are usually visible on the top of the engine, most of your wiring will also be exposed. Make sure not to place any wiring on surfaces where water can accumulate. Water can short-circuit the immobiliser and disable your ignition by accident. Secure the wires away from the hottest parts of the engine and insulate the end connectors to minimise the risk of faulty wiring.
Fuel System Immobiliser
To immobilize the fuel system, place an off switch on the fuel pump. Do not place wiring close to the fuel tank or the fuel leads, so try to cut off the power at the source. Each car has one or several relays that control the fuel pump, and they are located away from the fuel lines. Even if a problem occurs, it will probably just burn out the relay rather than starting a hazardous fire.
Starter System Immobiliser
A vehicle immobiliser on the starter system works by cutting of the power to the starter motor. The starter and the ignition coil are usually close by, so they can be a good combination for a stage two system. You can place the switch close to the starter motor, and you can secure the wiring to the existent power wires.