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The door sensor switch is a simple yet clever sensor which detects when the door is opened or closed.
The door sensor switch is usually linked to the car’s alarm and security system, so if the sensor switch detects unauthorised entry, by the car door being opened without the use of a key, the car alarm is activated.
This type of sensor usually works with a magnetically operated switch called a reed switch. The door sensor switch is hidden in the door frame and a magnet is placed on the other side of the door and this is all connected to an electrical circuit. When the car door is opened this moves the switch and the magnet apart, which makes the electrical connectors come together which sets the alarm off. The door sensor switch also activates the internal light/s in the car when the door is opened and the light/s are switched off when the door is shut again.
Faulty door sensor switches can mean the sensor will not detect an intrusion which jeopardises the safety of the vehicle. It can also lead to problems with the car’s central locking system and can cause the internal lights to either not come on when the door is opened or to stay on when the door is closed. These type of sensors will wear out over time. Damage to the wiring or to the sensor itself will mean you’ll need to replace this part. Buying a door sensor switch will ensure you’ll get the right part for the make and model of your vehicle.