I recently purchased a 1996 Mazda 323 protege shades and I believe it may have an aftermarket locking system on it as it has a key fob to lock and unlock the car.
After searching up the number on the back of the key fob it came up as a Cyclops TX74-A 3 black button black car alarm remote. Some problems that im having with it is that after turning off the car and getting out and closing the door the little red light on the dash will start slow flashing after a couple of seconds indicating that the alarm is set (the alarm is not going off its just set to go off hopefully that makes sense) and when I try locking the car it wont let me and the car thinks that its already locked but I can clearly see through the window that the doors are unlocked and I can open a door and the alarm will go off.
Also when the little red light starts slow flashing the car flashes its indicators thinking that its being locked.
Another thing is that the car will automatically lock if a door hasnt been opened after being unlocked but if the back left door is opened it doesnt detect that only door is opened and the car will still automatically lock itself thinking a door hasnt been opened.
Hopefully that makes sense and if you need any clarification or any more information just ask away and ill be happy to answer