Here's a breakdown of the challenges and potential solutions:
Challenges:
* Factory Alarm Integration: The factory alarm likely uses its own wiring harness and control module. Integrating a new motion sensor into this system is highly complex and likely requires specialized knowledge of the car's electrical system and the factory alarm's programming. You'd likely need a wiring diagram for your specific vehicle year and model.
* Power Source: Finding a reliable power source that's only active when the car is armed is crucial to avoid draining the battery. Tapping into the factory alarm's power might be possible but again, requires detailed understanding of the wiring. A better solution might be a separate, switched power source from the fuse box.
* Triggering the Alarm: The motion sensor's output needs to trigger an audible alarm. This could involve connecting it to an existing horn or siren (potentially overloading the system) or using a separate, aftermarket siren. This adds complexity to the installation.
* False Alarms: Motion sensors are prone to false alarms from things like animals, wind, or even temperature changes. This needs to be considered in the placement and configuration of the sensor.
Potential Solutions (with caveats):
* Standalone Motion Sensor Alarm: This is the simpler and more realistic approach. Buy a completely separate aftermarket motion sensor alarm system that is self-contained. It would have its own power source (likely a battery), siren, and control unit. You'd wire it independently, possibly using a switched power source from the fuse box to turn it on and off with the ignition. This won't integrate with the factory alarm, but it will add motion detection. This is the least intrusive method.
* Professional Installation: The safest and most reliable solution is to take it to a professional car alarm installer. They have the expertise and tools to assess your vehicle's system and safely install the motion sensor, minimizing the risk of damage or interference with the existing alarm.
Important Considerations:
* Wiring Diagrams: You absolutely need a wiring diagram for your specific 2001 Chrysler Sebring LXi. This will help you identify power sources and avoid damaging your vehicle's electrical system. These can often be found online (at a cost) or through a repair manual.
* Safety: Working with car electronics can be dangerous. If you're not comfortable with automotive electrical systems, do not attempt this yourself. Incorrect wiring can damage your car's electrical system or even cause a fire.
In summary, while technically possible to add a motion sensor, making it work *with* your factory system is very difficult. A standalone system is far more practical and safer. Consider the cost and complexity before starting the project, and always prioritize safety. Professional installation is strongly recommended unless you have significant experience with automotive electrical systems.
