Car theft or car break-ins are always a worry to the motorist and it is wise to take every precaution against them that you can.
Central door locking is a feature that provides both convenience and added security to anyone who regularly drives around with passengers in their car.
The most obvious advantage of a central door locking system is that it provides a quick and easy way of locking all the doors of your car together just by operating the driver's lock. The security gain is that there is no danger of leaving a door unlocked. You can also easily lock the rear doors to keep small children inside the car.
To convert your car to central door locking you need a kit, which you can readily buy from a car accessory shop. It consists of electrically operated drive units that you mount inside the doors, along with all the wiring, brackets and link rods that you need for fitting it to your car.
A kit can be used on a two- or four-door car, although the benefits of fitting one to a four-door car are obviously greater. It can also be used on almost any model of car, but you should check with your dealer first in case your car is unsuitable. It is also a good idea to shop around before you buy.
When the driver's door lock is operated it moves a switch in the master drive unit. The master unit then sends a signal to the drive units which move the link rods and lock or unlock the other doors.
Some kits are also supplied with a remote control. This allows you to lock the car from the outside with a hand-held unit. This has the advantage that, if the locks freeze in cold weather, you may still be able to unlock the door using the remote control.
Wiring central locking
Each drive unit has a small length of wiring attached to it which terminates in a multi-plug. The master drive unit is identified by having two extra wires connected to it. These are the feed and earth return for the entire door lock system.
Start by disconnecting the battery to avoid any short circuits. Join the terminal connectors to the ends of all the wires leading to the drive units. Remember there are four wires to the master drive unit and only two to the drive units.
Connect the wires to the multi-plug terminals making sure the wiring colours correspond. Route the feed wire to a permanent live feed such as the battery terminal or the battery side of the fuse box. Fit an in-line fuse (16 amp) to this wire. Run the earth wire to a suitable earthing point and secure it firmly.
Reconnect the battery terminal and test the lock is working correctly. Finally refit the door trim panel and window controls.