Sounds like normal behavior for the OEM Factory alarm. My sets whenever I lock my doors. The green will lite for a few seconds & then automatically turn off. Leave your window down, lock your doors & then reach in & open the door. This should set it off if your alarm is working.

really funny you said that, i've had my dsm for a year and first time i've ever seen the security light was today. Was really weird, also first time when I have my door open my overhead lights turn automatically on. I was messing with wiring hooking up gauges maybe hit something

Mine constantly goes off and the headlights flash. when i open the door to get out and the turbo timer is still on.

Yea mine will just go off now and then randomly when I unlock my drivers side door after its been locked for a little while. Just have to use the key to turn it off then. As far as the interior lights (BostonGST) probably the switch in the door jam is bad. Mine works sometimes and not others but if I fiddle with the switch with the door open I can make the lights come on. Usually they have to be working in order to see the green Security light come on on the dash.