Alarm constantly going off, DOOR AJAR, ENGINE light on, etc.

[outlier]

Hello all,

I have a 2002 Explorer XLT with 90K miles with some sort of electrical problem(s). It all seemed to start in earnest more than a month ago when the SERVICE ENGINE SOON light came on. Took it to the local mega-garage (with whom I am having some doubts) and they told me that it was an "1151" — it needs a new O² Sensor, which they said will cost $450.00. As I cannot afford that right now (and wanted to shop for a better price), I passed on the work.

About a week later, the SERVICE ENGINE SOON light went off on its own and has not turned on since then. We're not going to worry about this now, particularly as I am wondering if they weren't just BS'ing me and the light is actually caused by something else as evidenced by the other problems we're having.

Since that time, the alarm has been going off all hours of day and night. I would say on some days, it goes off several times a day. Other days, maybe once or twice or not at all. I've taken to disconnecting the battery ground cable when not driving it as I don't care to get up at 2:30 AM to take care of the alarm.

In the last week or so, the DOOR AJAR light has been frequently turning on. Checking the doors repeatedly will show that they are closed tight. Sometimes the light just stays on, other times, it flashes with the accompanying beeping tone. I've also started to pull over, disconnect the ground cable, reconnect the cable and restart, which seems to temporarily take care of the problem. When reconnecting the cable, this trips the alarm.

FWIW, the Explorer has some type of dealer-installed or premium alarm system , of which there was some debate about on a previous thread. Linked below is a photo of the manual, if it helps ID the alarm. Any help would be greatly appreciated.

Thanks in advance.

 

[Exproblems]

Since that time, the alarm has been going off all hours of day and night. I would say on some days, it goes off several times a day. Other days, maybe once or twice or not at all. I've taken to disconnecting the battery ground cable when not driving it as I don't care to get up at 2:30 AM to take care of the alarm.

In the last week or so, the DOOR AJAR light has been frequently turning on. Checking the doors repeatedly will show that they are closed tight. Sometimes the light just stays on, other times, it flashes with the accompanying beeping tone. I've also started to pull over, disconnect the ground cable, reconnect the cable and restart, which seems to temporarily take care of the problem. When reconnecting the cable, this trips the alarm.>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Try the link below, and look at post #3 by "BigRondo". He has two links in his post that can help you with your door ajar problem and the alarm going off issue. Your problem could have to do with a bad door ajar switch and a broken wire in your driver side door boot.

http://www.explorerforum.com/forums/showthread.php?t=294764

 

[BigRondo]

Here you go:


I had similar electrical issues with my 02 xlt. The dome lights would stay on until the battery saver feature turned them off, the accessory delay wasn't working, the driver side puddle light didn't work, the keypad on the door would set off the alarm when I pressed it, the door ajar light would flash and beep at highway speeds, the radio would shut off as soon as I turned the key off, the delayed accessories didn't work, etc. Most recently all 4 windows stopped working.

A lot of electrical issues can be traced back to broken/damaged wire(s) in the boot between the body and the driver's door. I found 2 broken wires and repaired them. The thin black ground wire was broken and after repairing it all was back to normal. When the windows stopped working, I repaired the thick black ground wire and the windows now work like a champ.

Here is the thread for removing the door panel: http://www.explorerforum.com/forums//showthread.php?t=303524

Here is a great thread for checking for broken/damaged wires, thanks to synyster for this awesome write-up: http://www.explorerforum.com/forums//showthread.php?t=270081

Be sure to take your time when looking for broken/damaged wire(s). Check all the wires for breaks/damage. When you think you're done looking, look again, and again, and again. A bright flashlight can be very helpful.

Could also be related to the door ajar switch.

Here is a great thread for checking/replacing the door ajar switch, thanks to borland for the awesome write-up: http://www.explorerforum.com/forums/showthread.php?t=249253

That is a great write up.

On a side note, before going through a complete replacement of the switch, you can spray WD40 into the door latch opening on each door, as these become stuck sometimes....and this can alleviate the issue.

This worked for me, after going for more than a year of the "door ajar" light coming on occasionally...mainly after a car wash, high humidity, or rain....making me unable to lock/arm the vehicle from the door keypad and keeping the dome lights on. Worth a try....it worked for me

Good luck and be sure to keep us posted.

 

[outlier]

Good stuff. Thanks! Going outside shortly to work on the Ford. I've worked as an electronics repair tech, so I have an idea of what to look for here.

Of course it makes perfect sense about the correlation between the DOOR AJAR light and the alarm going off as the Ford would "think" the door is being opened. We did notice that the passenger side front door would of course show as DOOR AJAR when open and then when closing, the light would turn off and then within a half second, the light turns back on and beep as well. This was happening consistently last week as we opened and shut this door, so this is the first place I will look.

 

[outlier]

Had a delay in getting to it until today. Here's what I found: As mentioned above, my first thought was of the passenger side front door. Disassembled the door, looked at the wires, nothing looked broken. Ground wires are thinner as mentioned. Got out the multimeter and checked for continuity between a chassis ground and the ground wires' connectors. Even shaking the wires, there was a solid closed circuit with the display reading "Shrt". So everything seemed fine as far as the ground wires are concerned. Poked around and saw that there is a plastic molex type connector between the door sensor and the wiring. In my experience as an amplifier repair tech, mechanical connectors are always first suspects as oxidation can build up and create an intermittent or open circuit. The connector can be disconnected by moving a red flange, which exposes the tab to push to disconnect the two sides. Took them apart, examined for telltale signs of corrosion or oxidation, wasn't really seeing anything too obvious, but squirted the pins and socket down with WD-40 (I know, should've used contact cleaner, but the WD-40 is what I reached for). Added some bulb grease to help keep out moisture, reassembled. After two test drives, NO beeping or DOOR AJAR light.

So one might also look to these connectors as being the culprit as well. Fingers crossed, but looks like problem solved.

 

[BigRondo]

Nicely done!!

 

[borland]

Your original description of the symtoms indicated the problem to be intermittent. Hope you found the problem, time will tell if you need to remove the panel again.

Sometimes it is better to replace a questionable low cost part in order to avoid reworking the problem later.

 

[skysthelymyt]

I had the same problem. Just a simple fix. Spray the door hinges with some type of spray lube (I used PB blaster) and I have not had any problems since.
About the check engine light. It is an O2 sensor. However, that doesn't mean that you have replace it. Sometimes in a rapid weather change (getting hot to cold really fast) it can change the way the engine burns the fuel causing the O2 sensors to go crazy. A OEM Motorcraft O2 plug should be about 80$. Not 450$ (I know, that includes labor). It's not very hard to change it yourself and save some money. Just find out which O2 sensor it is.

 

[outlier]

Well, about the DOOR AJAR light, it worked for a while, but about two weeks ago, the beeping and the light started going off again. And of course, the alarm started going off at all hours...

So, disconnected the battery cable as an interim "fix," just so the alarm would stop going off. Yesterday, started it up and took it for a short drive. DOOR AJAR light came up with starting the engine and stayed on with no beeping at all. So this is something a bit new. Shut off the engine, disconnected the battery a few times, restarted, DOOR AJAR light is on steady, no beeping. Spraying the door hinges did not work, unfortunately.

So today, I am going to open all of the other panels, disassemble the connectors, clean them, apply some dielectric grease and then reassemble. It should take a little while, but hopefully it'll work.

About the SERVICE ENGINE SOON light, it hasn't lit in months, so maybe I'm being foolhardy, but I'm not worrying about it at all. The explanation about weather changes also seems perfectly possible as when I originally posted, that's about the time the weather rapidly changes here in Tennessee from cooler to summer-like weather. Around here, it can change in a day. One day, we'll have the heat on, the very next day, the air conditioning.

 

[outlier]

Spent all day on this, nothing's worked yet. I did find a good thread here:

http://www.explorerforum.com/forums/showthread.php?t=249253

Tried opening the windows, arming the alarm, waiting and then opening the door from the inside. Sure enough, it's the front passenger door again. Opening the door did not set off the alarm.

Tried disassembling the AJAR switch, cleaned it, the button on it seemed mechanically sound, reassembled, checked for continuity on wires, that was A-OK. Still didn't fix it. I suppose the next step is to replace this switch. I hope that works...

 

[BigRondo]

I would recheck for broken/damaged wire(s). They can be a bugger to find.

 

[outlier]

As I wrote, I worked as an amplifier repair tech. First thing I look for are mechanical connections such as molex connectors (if present) oxidizing on the contacts, next is broken wires. Naturally, any wire subjected to back and forth motions has the potential of fraying (in the case of stranded wire of course) and then eventually breaking entirely. They can become intermittent as the back and forth motion will occasionally touch the broken portions.

Both of the above are sound. So I'm going to give a shot at ordering a new AJAR button/switch and see if that doesn't take care of it. We shall see!

 

[outlier]

Just called a local Ford dealer and they want $90.00 for a passenger-side door jamb/AJAR switch for a 2002 XLT... A little pricey for me right now. Anyone know of a good online dealer for this part?

 

[keith001]

Man, I got the same problem as you do.
years ago, my 02 explorer xlt had the ajar door problem. The problem was that when you insert the key without cranking the engine and during driving , the ajar door light will be there. And the lights inside would be still on with the door being locked. I used some lubricant to lubricate all the door latches. It worked till yesterday.
Now the problem is more complicate. with all doors closed, there is no warning light when I inserted the key and rotate to the position but without starting it up. After I started up the vehicle like 30 seconds, the ajar door light was on.
the security system was honking all night long sometime after I locked the door last night. I didn't realized it until early this morning when my neighbour knocked at my door.

instead of door jam switch and broken wires, is there any other possibility?
How did you get it fixed?