Have been back to the dealer 3 times because door ajar light & tone goes off randomly! Sometimes if I hit a bump in road it goes off! The light stays on in spite of repeatedly slamming door! They tightened door on 1st visit! ( I did not like the tension that placed on the door) Sounded terrible! I had to return to get the door switch replaced & then when it recurred again, they replaced the latch mechanism! Now it’s starting again!
This is a fairly common problem with Ford trucks. Either the shop didn’t work on the correct door switch or the trouble is at a different location on the circuit, perhaps the door jam.
Service manager at Ford Dealer said they had no protocal for this problem! Go figure!