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Q: door ajar indicator on 2002 Mercury Mountaineer

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with all the doors closed and locked, the door ajar indicator is on. Often while driving the locks will unlock and relock.
Is the emblem on the back hatch have a crack above or below it? If so, this is what is causing the door adjar lights/messages. Because it can flex, the sensor sees it as an open circuit. Crappy ford plastic, that is why they redesigned the rear lift gates on the new Mountaineers and Explorers. Ford TSB 0485 addresses this problem.
I have a 2002 Mountaineer and it has been doing the same thing.'' The locks go bonkers and then "door ajar" will stay up there for days. The alarm actualyy sets off by itself every now and then because it unlocks itself. I just took it to a mechanic, and he;s telling me I need a new computer. I explained that it fixes itself but to no avail.
Took it to the dealer and paid $100 for them to put oil on the locks and they started working again. So try oiling the locks before you waste money like me.
I've had the same problem and dealer replaced dooe alarm switch at the cost of $300.00
Thanks tygermoe - you just saved me $100 (or more depending on what they would have tried to replace) and probably a couple of hours at the repair shop.

My 2004 Impala was leaving the door ajar light on and sometimes locking and unlocking the door for the past week. Also the interior lights stayed on. It has no visible door jamb switch, so I concluded that it was incorporated into the locks for each door.

Just went out and hit all 4 door locks with my can of Slick 50 (safe for metal, plastic, and rubber) and then opened and shut them all several times - and like magic the door ajar indication light is no longer coming on!!

Thank you for being a God-send. I was let go from my company (in June) after 9 years due to the economy, and I have been doing contract work to pay the bills (I'm a giver and not a taker) - so the point is, every dollar helps. Thanks again!
i may be a little late but i had this same problem and found a broken wire inside the rubber boot between the driver door and dash. sometimes it made connection sometimes not. you might try this.
I have had all these problems and have spent the last 20 min trying to get the interior light to shut off. So frustrating but after reading this I got out the WD 40 hit the locks a few times and the light shut off as soon as the door closed. As far as the locks and alarm goes we'll have to see but at least the interior dome light is off. Thanks!!
We have a 2003 Merc Mountaineer which had the "door ajar" indicator and courtesy lights would not turn off after parked. Read your articles, went out to garage, sprayed all 6 locks (4 doors, rear window and rear hatch)and then opened and shut each about 10 times. Lights went off in about 25 seconds and no more "ajar"! We had been quoted $370 from dealership who told us that in time, all sensors would go bad. 6 times $370 = $2,220 the dealership just lost! Thanks so much!
I had the same problem. I soaked all the locks with WD40 and opened and closed all the doors over 12 times. It worked!
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