I just replaced my alarm siren with the new one that chirps. I had no indication that anything was wrong with my original so I was wondering if it had been replaced before.
This is why I'm curious about the build date. Thanks in advance for any information. Looking at what I think is the date code, my guess is January 2nd, 2004.

 

Considering the one you showed us has the torx screw threaded into the alarm I suspect it is the OEM alarm.
I suspect the replacement alarm that chirps has the threaded stub attached to the alarm
and ya needed to place a nut on it to tighten it down when you installed it

My new Alarm has this threaded stub attached

 

I believe it to be the original also. I was just curious to know if they had made any replacements prior to the new ones with the stud.
The one I replaced it with did have the stud and needed an M8 - 1.25 nut.
Thanks for the reply.

 

When I replaced my alarm I had the choice of alarms with and without the stud. I have a post here somewhere showing the alarms and the part numbers.
Edited to show the two part numbers.

 

I'll look for that post. Thanks!