What Causes a Car Alarm to Sound?
1 Answers
The reason a car alarm sounds is due to a fault in the main control door ground wire. When the sensor is struck or shaken, causing it to vibrate, a small ball inside the cylinder chamber rolls. As it rolls away from a smaller secondary electrical contact element, the circuit formed by this secondary contact element and the central electrical contact element is broken. At this point, the switch opens, alerting the controller that the ball has moved. As the ball continues to roll past other secondary electrical contact elements, the circuit will repeatedly close and open until the ball finally stops rolling. If the sensor experiences stronger vibrations, the ball will roll a longer distance, passing more secondary electrical contact elements before coming to a stop. If this happens, the controller will receive short pulse currents from all the individual circuits. The controller can measure the intensity of the vibration based on the amount and duration of the pulse currents received. If the ball only rolls from one contact element to another, the controller will not trigger the alarm at all. However, if a significant displacement occurs, such as someone hitting the car, the vehicle will emit an alarm signal: the horn may sound briefly or the headlights may flash. If the ball rolls a longer distance, the controller will fully activate the alarm. Solutions for a Car Alarm Sounding: Locate the wiring distribution of the anti-theft system, which is generally found under the steering wheel or behind the A-pillar trim. Simply disconnect the input wire of the alarm, rendering it ineffective. Some alarms have fuse protection, in which case you need to locate the corresponding fuse (refer to the car repair manual) and remove it to deactivate the car's anti-theft system. If the issue lies with the main alarm unit's wiring, it requires timely inspection, repair, or replacement. However, whether it's checking the wiring or replacing the alarm, it's best left to professionals. This task is beyond the average person's capability, and the system involves many integrated wiring connections. Improper installation or reversed wiring could result in the alarm not functioning or, worse, damaging the vehicle's internal components.
