Do car alarms go off if the windows are broken?

Question

This may seem like a stupid question but the windows on my car were broken by vandals and when I got there, the car alarm wasn't going off which I found strange. Do car alarms actually go off it he windows are broken? Thanks

Answer 1

Cars are fitted with Ultrasonic sensors.

These will detect 'Shocks' or any form, not motional.

Modern cars have motional aswell.

If the car is fitted with an alarm, and you break the glass :

YES - It will Go off.

GDJ.

Answer 2

The impact of breaking the windows should set off the alarm. However, car alarms usually stop sounding after 30-45 seconds, so it's possible you just missed it.

Answer 3

Not all alarms have sensors to activate it in the event of a window break.  

Answer 4

yes

Answer 5

They should have. Was it an old car?

For the most part, car's with alarms are usually alot more sensitive then that. For instince even bumping into them 2 or 3 times should set off the alarm.

Answer 6

Only if the alarm has a volumetric sensor to monitor the airpressure. If it doesn't then the alarm won't sound.

Answer 7

they normaly do yes

Answer 8

Yeah like these guys said, you probably just missed it.

The car alarm should of picked up the impact when the window was smashed but also most cars now have motion sensors inside which would pick that up and set off the alarm.

Shame them bums did that to your motor.

Take care

James

Answer 9

Yes, it should. But most alarms will shut off after a several minutes.

You probably just didn't hear the sound of it.