Car Alarms: 1999 F250 car alarm.......door trigger, domelight, steering column

Question
What wire do I use as the door trigger and is it "+" or "-".
I tried the blck with blue stripe on the grey plug beside the steering column but it doesn't seem to change as the door opens or closes.
I also wired right to the door ajar wire in the door but after 30 mins or so the alarm always comes on by its self..........?

Answer
DEI lists this for the door trigger:

Door Trigger    black/lt. blue     +     gray plug right of column

This wire should go to +12V when the door is open and to ground when the door is shut, after the domelight extinguishes.  You will also be able to find the wire going up the pillar to the domelight itself.  If you want to use the door pin as you found in the door you will need to diode isolate it and use the one from both doors which would require running a wire into both doors.  After about 30 minutes your BCM goes to sleep, and when it does it changes the state of the wire.  Your alarm is reading this change of state and interpreting it as the door opening.  Diode isolating it will prevent it from falsing.