Chrysler Repair: Door Sensor/security system non-function

Question
I have a 2004 Grand Cherokee Jeep . I have an alarm system and the alarm will not work because I was told that the door sensor is not properly functioning causing the alarm not to trigger. What must I do?

Answer
Hi Sandra,
Was that diagnosis based on a fault code? If so, if you might have that 4-digit number that would be helpful to know.
The door latches include an ability to notice if the door is ajar when you think it is closed, but the latch could be erroneous.
The alarm system will not 'arm' itself if it thinks that one of the doors is ajar. The cause for it believing it is ajar is integral to the latch itself, so generally if it is falsely reporting the door is ajar the latch mechanism needs to be replaced.
Does the instrument cluster indicate that one of the doors is ajar when it really isn't? If so, then that would be the latch to consider for replacement. Ideally there should be a corroborative fault code, and ideally an electrical test done of the latch wiring. If all proves o.k. then replacing the door latch would be the solution. However, a fault code number would be helpful to know.
Please read the PS (below) and respond to it.
Thanks for doing that.
Roland