I decided to try and set my alarm off the other day, just to see what it sounds like. I left all the windows down, and set the interior detectors with the button next to the drivers seat. Waved my arm in the car. The indicators flashed, but no alarm sound. Does anyone know what this could be, or had this problem? It's worried me since i found out. The horn works from the steering wheel ok. Does the horn act as an alarm siren? any help appreciated!