The alarm on my wifes 2000 TL keeps going off like ten minutes after locking it then we will reset it and it will go off a couple minutes later and again and again. but it only does this like once a day for about 30 minutes or so sometimes more. i think it might be beacause i put an aftermarket stereo in it. so does anyone know how to make it stop??

 

depending on what you did to the wiring there is no way for us to know what has been altered. Can you directly link the symptom to the replacement of the stereo or no? if you don't set your alarm and you observe the car do you notice the interior lights come on? does anything odd happen when you are driving like the door or trunk light on your dash coming on? Your system works on 6 sensors I think: 4 doors, trunk, and hood. If any of those switches is on the fritz then it will trigger the alarm.