Just for you to know if it ever happends to come back in the future. Most of the time The door Ajar light comes on from a sticky door latch. I've fixed hand fulls of cars and trucks that had this problem. Easiest fix in the world.... All you have to do if spray a lot of WD-40 on all for door latches since you don't know which one is the sticky one making the door ajar light come on. You really have to spray a lot in it, I mean to the point where it comes out of the bottom of your door. It fixes is everytime! I just fixed my freinds mother who has a 98 Windstar of the same problem. She had an appointment with a Ford dealer to have it checked out, but I was able to fix it just by WD-40!
This is just to let you know if if every happends to be stuck in the future sometime, saves you a trip to the dealer thats for sure.