it senses the position of the lock so the other doors wont lock when its open, but the zapper only locks the other doors and not the drivers door, their is power going to the solenoid as if you hold a multimeter on the terminal you get the 12V spike when it tries to lock but nothing happens, may be a loose connection inside or something but it seems to be glued together, can see and screws or means of opening to find out
I don't want to saw it open with out the ability to replace if it all goes wrong...
