Car alarms are equipped with sensors located throughout the vehicle that act as detection devices. The most common sensor is linked to the doors. When the alarm system is operating and the door is opened, the sensor communicates this to the brain. The brain sends a signal out to the alarm system components such as the lights, siren or horn to alert the owner of a possible theft. Other sensors respond to impacts on different areas of the vehicle. If you believe the sensitivity is too weak on your car alarm, you can increase it to respond better.
Find the shock sensor located underneath the driver's side dash. It resembles a small black box about 4 inches in diameter.
Locate an adjustment dial or inset screw on the side of the shock sensor. Rotate the dial clockwise with your fingers, or with the blade of a flathead screwdriver.
Slap the four corners of the car with the palm of your hand. Take off any jewellery that could damage your vehicle's finish before doing this. Increase the alarm's sensitivity if the alarm does not sound when performing this test.
The location of the shock sensor varies on where the installer attached it. It might be located below the steering column or another accessible area. More disassembling of the vehicle may be required depending on where the sensor is placed.