I just recently started having trouble with my factory installed alarm system. Whats happening is when I press the lock button on the key pad the doors will lock and the horn will chirp twice, just like always. But when I press the unlock button the doors will unlock with no horn chirps (the horn used to chirp twice), and if you open a door the alarm will sound. The couple times it happened I was able to get the alarm off but repeatedly pressing the unlock button of the FOB. With this in mind I figured it was the batteries, I changed them but it still does the same thing. Has anyone out there had anything like this happen? And if so how did you get it fixed...Thanks