I have a 2000 Ranger that the dash "Door Ajar" warning light has started to remain on as well as the dome light remains one for a couple minutes after I start the vehicleand begin to drive.The dome lightwill alsoremain on after parking the vehicle and shuting it off. After I park it thedome light will remain on for an extended period of time, not sure how long. The "Door Ajar" light remains on continuosly aslong as the vehicle is running.Today I disassebled the divers door and checked the operation of the switches on the latch mechanism and they seem to function correctly. I plan to check the passenger door tomorrow. This problem appeared a year ago during the cold weather but dissappeared afterI lubricated the door laches. Now again with cold weather here and after being washed good the problemreappeared, then dissappeared after I let the vehicle set in a warm garage over night but it reappeared in a couple days and now will not go away. Any suggestions and advice would be greatly appreaciated. By the way I had a 1995 Ranger that had begin to experience the same problem just beore I traded it it off.

 

That is almost always the switch on the door latch. Usally spraying WD40 into the latch and shutting the door a few times will fix it.

 

Yah its your door switch. You can get them at napa for less than $20

 

jr78 is on the right path. The sensor is in the door latch and they get dirty and stick. Get a can of WD-40 with the straw on it and give both latches a liberal dose of WD and open and close the doors several times. I've had to do it on every Ford truck I've had that was a 99 or newer.