Interior lights and door ajar light goes on and off while driving

My 1999 Ford Expedition has the interior lights go on and off while driving and the door ajar light is on most of the time. When I close the driver’s door the interior lights stay on and sometimes my battery goes dead. I’m thinking it’s a door sensor. If so, is this easy to replace on my own or do I need to take it in? Please let me know what I can do to solve this issue. Thanks!

If it’s the same setup as my 98 Windstar, the door switch/sensor is built into the door latch. Before you replace anything, spray some electrical contact cleaner or WD-40 into the door latch while working the handle. Hopefully this should help. Let us know if it works or not.

Ed B.

Clean and adjust the door sensor and check for possible broken wires or connections at the door.

We’ve had this one before. Apparently this problem is common with many types of Ford vehicles of that vintage. Most owners report success with Ed’s advice above.

Thanks for your advice on this. Your suggestion to use a lubricant, like WD-40, and spray the latch did the trick. Amazingly simple! I haven’t had a problem since.