'05 Ford Explorer Interior Lights/Door Ajar

[Dellfin]

So, I starting having this issue around the first of the year...Airjer..?

I turn the SUV engine off and leave the key in the ignition. The chime starts dinging before I open the driver's door. It should only start chiming to let me know the key is in still in the ignition after I open the door. If I leave the door closed and remove the key and the chime stops. I exit the SUV and shut the door. The interior courtesy lights stay on a long time...too long. Eventually (5+ minutes?) it shuts off. I assume this is because there is technology that prevents the battery from draining too low when a door is inadvertently left open.

If I turn the SUV off, leave the key in the ignition, exit and shut the door the chime continues as if the door is still open. Again, eventually (5+ minutes?) it will stop chiming and the lights will shut off.

I have Googled causes and found many comments that a switch in a door lock mechanism can stick or fail and indicate that a door is still open when it isn't. I assume that this could be the driver's door, but don't know for sure. The suggested "poor man's" fix is to WD40 the heck out of each door mechanism and let it penetrate the stuck switch/sensor. After a few tries at that the issue remains. So, I've been turning the dial that controls the intensity of the courtesy lights off until it clicks after each drive.

Now I find that when I turn the courtesy light dial switch to either the stay-on or auto the door lock button on the drivers door armrest will not power lock/unlock the doors; the switch is dead. The passenger side power lock works fine and locks/unlocks all of the doors. Rolling the courtesy light switch dial back off until it clicks and the driver's side power lock switch works fine again. The key fob works fine unlocking all doors with the courtesy light dial switch in any position.

I assume I have either a bad sensor in one of the doors lock switches or a short somewhere, but I have no idea on how or where to begin diagnosing. I started by thinking I'd clean the contacts or replace the switch in the driver's side door power lock button, but that can't be it if the switch works OK with the courtesy lights off.

I'm at a loss. Any thoughts?

[Scott K]

Well i am not Airjer, but maybe I can help.

We will start off with the dome light, being the door chime is dinging with the key in the ignition, that tells me it is the drivers door ajar switch that is sticking, the switch is mounted to the bottom side of the door latch, to access it to replace it, would require removing the door panel, and twisting the old one off, and twisting the new one on. You can try to clean, and relube, and open and slam the door a bunch of times, this will usually buy you a few months, before dirt sticks to it, and causes it to stick again.

As far as your door lock switch not working, a little research tells me your door lock switch, and the VSM share the smae ground G401, before getting to caught up into diagnosing it, I would check ground G401, it is located in the rr of the vehicle.

After that, having a scan tool that can read the PID info would be of great help, to find out if the VSM is getting the info from the switch, when the dome light switch is turned in the on position. Without the scan tool, you can still diagnose it, but it would require you to back probe the electrical connectors at the VSM and see if the switch input is getting to the VSM or not.

[Dellfin]

Wow...you are my my new automotive advice hero, 4wanderingeyes (sorry Airjer). Thanks for the tips on where to start.

[Scott K]

If you have any more questions, feel free to ask. Remember, there are no dumb questions.

[Dellfin]

OK, here is a twist for you to ponder. Courtesy light switch/dial is on auto. Pull in the garage last night, turn off the ignition, leave the key in the ignition, open the door and get the chime. Shut the door and the chime continues as if the door is still open. I reach in through the open window and turn the courtesy lamp dial/switch to the off position and the chime stops. Could this be an indicator that the dial switch for the courtesy lamps is bad or has a short?

Also, I assume that if the door ajar switch is bad it is the driver's door switch, but I'm not sure. Is there a "simple" way to test each door before I start replacing to make sure I have the correct one?

[Scott K]

The simplest way to diagnose this would be with a scan tool, because you can read which door it thinks is open. Other then that, you would need to remove the door panel, and unplug the door ajar switch. Being that it is dinging with the courtesy light switch, I would check that ground wire first. I also see G400 and G401 controls different circuits in it. I would check both. G400 is in the left rear.

[Dellfin]

Thanks for your help, Scott!

[bwa]

Check the wires in the drivers door jam harness. These are known to break. I imagine a ground wire is broken in this location, & possibly there may be others broken there as well. You will have push the boot into the body to see the wires in question.

[Dellfin]

While I try to find a solution to this issue something else began happening. I was downtown pulling into a parking ramp and had to crank the wheel really hard to the left at a super slow speed in order to make a turn and hear a faint "clunk". I notice after the turn that my 4WD High light is illuminated on the dash indicating that the 4WD has engaged. I push the 4WD auto button on the dash and it goes back to normal.

About 2 weeks later I'm pulling a trailer with some brush and make a normal right hand turn at a stoplight and I feel the 4WD engage all by itself. Look at the dash and sure enough it says I am in 4WD High. I again push the 4WD auto button and it goes back to normal.

So now I'm beginning to wonder whether I have an electrical problem gremlin who has begun to inhabit my Explorer and this is just a sign of more things to come.

Any thoughts on this one..?

[bwa]

I suspect the 4x4 concern isn't related to your previous concerns with door ajar/lights/etc. While false 4x4 engagement concerns are somewhat common issues with this truck I find it strange that the 4x4 HIGH light on the dash illuminates, indicating that the button was actually pressed. Is your ABS light coming on too? What about tires, do they all match (tread depth, size, model)? There are several things that could cause false 4X4 engagement but not sure about your dash light coming on...have you checked the wires in the door jam yet? I would chase that issue 1st & see if the 4X4 persists. A broken ground wire here will cause several issues.

[Dellfin]

I did check the wiring inside the driver's door panel. I looked at all of the connectors and made sure there was no moisture/corrosion and everything "looks" fine. I've since determined that the issue doesn't seem to be isolated to the driver's door so I think I've ruled out that door being the issue.

I stopped in at my regular mechanic today to ask his advice. He immediately focused in on the ignition itself. He sprayed some graphite lubricant in there and worked the key around. We'll see if that does anything, but I remain unconvinced.

We then discussed the 4X4 issue and he said that he's seen it before and probably will eventually require replacing the electric motors that drives the worm gear that puts the front hubs into play (either electrical or vacuum driven...he wasn't sure without looking it up). With whatever other failed parts he ball-parked it at between $500-700 per side because of extensive labor in tearing down the hubs. I asked what could be done in the meanwhile and whether continuing to drive it would be making things worse, and more expensive, later. He said that until it actually fails there isn't anything he knows of that will prevent it and to just keep driving.

My thought is that if it's happened only twice, and only while making a turn, maybe something like a vacuum line pinched or an electrical connection losing continuity is the cause and a simple fix now could prevent a catastrophic failure later. I've been dealing with him for many years and trust him, but this sounds a little like throwing in the towel before the first punch is thrown. I suppose I could ask him to put it on the lift and do a visual inspection. But, if he's right about it being inevitable I don't want to spend that money now for something that can't be avoided.

I was hoping one of you guys would say something like, "oh yeah, that's your 'acme shim-nut' and it just need to be tweaked two turns to the left." I guess I should have been a mechanic instead of an aspiring billionaire. Rats.

[bwa]

Check the wires in the door hinge area, not in the door itself but where the harness goes into the door. Open the drivers door, look at the black rubber boot between the door hinges, the wires inside there tend to break due to years of flexing when the door is opened. You can pull the boot out of the door & trim off the taped portion, push the boot toward & into the cab hole (away from the door) to expose the wire harness. Look at the thicker guage wires, they tend to break first.

[Dellfin]

I finally got tired of the issue and bit the bullet to have the shop take a look. It was a broken wire in the wiring harness between the door and the chassis.

"bwa" gets the prize. Please collect your winnings at the door.

FWIW, the 4X4 issue hasn't occurred again. Not sure if that's an issue I'll need to deal with down the road, but I suppose you can't fix something that's not broke.