This was the only symptom I had and a good spraying of the latches on each door including the back lift solved the problem for me also.

 

Same problem here.
Dealer fixed under warranty (2x) and I have to wonder if they just did the lube thing...........

 

I had the same Door Ajar message and double horn when trying to lock my 2003 EB Expedition today. First time its ever happened. I searched the forums as to what might be causing the issue since all the doors/tailgate/window were definitely closed and locked.

My search results came down to two different strategies. 1) Use WD40 which seemed to frequently work but then seemed to require repeated sprays over time and potentially "gummed" things up since it also acted as an attractant for dust and debris. 2) Purchase and install a replacement part - which if you read the details is a non-trivial amount of work.

I decided that before I tried the WD40 method or started tearing the door apart that I'd try some compressed air (from a can) to see if the issue might be resolved by blasting out any loose debris that might be causing the problem.

Happy to report that within 60 seconds I had resolved the issue and everything is back to normal.

 

I put mine on the scanner and found which door was causing the problem. I will be taking your advice concerning the lite lube spray. My brother works for Advanced Auto so he told me which spray to buy. However, my mechanic said the parts aren't that expensive from the Ford company. The door sensor is about 30 bucks and the sensor needed to replace under the hood is about 50.

 

Hi guys one culprit is also the door lock mechanism. In my case I need to replace the lock strikers. Or at least the little tubes/bushings. They are worn out or totally broken off. Alarm goes off, Door ajar comes etc.

Now here's the boner... I have bought two sets of bushings - TOO BIG!
I bought the whole set of four strickers. The seller's site said it was for my vehicle. I checked the reference at other sites and got it confirmed. When I received them they were TOO BIG!!!!!! Boy o Boy!!!

I have a 1998 Ford Explorer XLT with very low mileage so refurbishing rather than replacing.

Any help guys on WHERE I can find the REAL strickers or bushings for my doors.