2002 Explorer Door Ajar Warning Light

[cwoernle]

I have a 2002 Ford Explorer. For some time the door ajar warning light and the alarm sound would come on intermittently, even though the doors were all shut. This usually started after making a turn or hitting a bump. The problem occurred during a diagnostic test drive with the dealer's technician. His computer indicated a problem with the rear hatch. The technician said he would have to replace both sensors in the rear hatch and its window, since he could not tell which one was faulty. I replaced both sensors, and now the door ajar light stays on continually but thankfully the alarm sound has not gone off. However, the door ajar light will go off if the rear hatch or its window are open!
I can live with the door ajar light staying on as long as the alarm does not go off. Any ideas?

Follow-up: I used an ohm meter to test the two sensors I removed. They behave exactly opposite. The one shows a closed circuit until the button is pressed in. The other shows an open circuit until the button is pressed in. I presume they both can't be correct, since they are supposed to detect an unlatched door. So replacing one of them was necessary. But it still does not explain why, with the new ones in place, the door ajar light goes off only when the window on the hatch is open.

 

[Rick]

I'm moving your thread into the stock 2002-2005 Explorer sub-forum.

 

[BigRondo]

I have a 2002 Ford Explorer. For some time the door ajar warning light and the alarm sound would come on intermittently, even though the doors were all shut. This usually started after making a turn or hitting a bump. The problem occurred during a diagnostic test drive with the dealer's technician. His computer indicated a problem with the rear hatch. The technician said he would have to replace both sensors in the rear hatch and its window, since he could not tell which one was faulty. I replaced both sensors, and now the door ajar light stays on continually but thankfully the alarm sound has not gone off. However, the door ajar light will go off if the rear hatch or its window are open!
I can live with the door ajar light staying on as long as the alarm does not go off. Any ideas?

Follow-up: I used an ohm meter to test the two sensors I removed. They behave exactly opposite. The one shows a closed circuit until the button is pressed in. The other shows an open circuit until the button is pressed in. I presume they both can't be correct, since they are supposed to detect an unlatched door. So replacing one of them was necessary. But it still does not explain why, with the new ones in place, the door ajar light goes off only when the window on the hatch is open.

Welcome aboard!!

Here is the wiring diagram for the switches. You can see that the circuit is closed when the door/liftgate/liftgate glass is closed:

Testing the switch:

• Verify that plunger operates freely.
• If plunger does not operate freely, try using WD-40 or similar to free up plunger. If plunger cannot be freed up, then replace switch.
• Once you have verified that the plunger is operating correctly, proceed to the next step.

Use a meter to test proper operation of the switch:

• Set the meter to continuity.
• Place the probes on each of the pins on the switch.
• Since the plunger isn't pressed in, the switch is open and there should be no continuity.
• Press in the plunger. This closes the switch and there should be continuity.
• If the switch does not operate correctly, replace the switch.

 

[cwoernle]

BigRondo, this is very helpful. I tested the two sensors I removed, and the one from the liftgate does just the opposite--it shows continuity when the plunger is not pressed in and no continuity when it is pressed it. So it had to be replaced.
I wish I had tested the new sensors I bought (not OEM but local autoparts store) before I put them in. As I mentioned above, with the new sensors installed, the door ajar light now stays on UNLESS the tailgate or tailgate glass is open. Seems to be just the opposite of how it should work. At least the alarm is not going off.
Thanks again for your input.

 

[BigRondo]

So it looks like you have the wrong switches. Do you plan on getting the correct ones?

 

[cwoernle]

The switches I bought were listed by the autoparts store as equivalent to the OEM part numbers the Ford dealership provided. And the switches I removed had those OEM part numbers. I don't know if I'll bother to pull out the new switches and check them, because getting to the one for the window was a real bear. If the alarm starts going off again, I reckon I will.

 

[BigRondo]

Ok. Good luck to you Sir!

 

[cwoernle]

Do you think it's possible there is a problem in the central security module?
Thanks for your help.

 

[BigRondo]

Do you think it's possible there is a problem in the central security module?
Thanks for your help.

The door ajar switches close the circuit when the doors/liftgate/liftgate glass are closed.

You stated that you had one switch that opens the circuit when the doors/liftgate/liftgate glass is closed. I would start by replacing this switch with one that operates correctly and see if that fixes the issue.

I will check my shop manuals when I get home tonight.

 

[cwoernle]

Thanks again for your help.

 

[BigRondo]

I can send you the steps for testing the Central Security Module, but I need to know if your build date is before or after 03/2002.

-- Rondo

 

[cwoernle]

The build date was before 03/2002. (I bought it in November 2001).
I read some other posts you commented on in the past. It is also possible there is a broken wire, because some of the problems of this car are similar to issues raised in the broken wire threads.

Thanks for your help.

 

[BigRondo]

It is absolutely possible that you have a broken wire.

You said you had a switch that was operating incorrectly so that's why I was going in that direction.

 

[severtecher]

You really don't need diagnostic testers to check this problem. Just get the light and buzzer to stay on and grab the glass hatch. Push, or pull on it and see if the warnings go away.
I have had the same problem and removed the glass hatch latching assy last weekend. The switch functions fine but it is a poor mount design and it may need a new latch assy that comes with a new switch. They want $50 for a switch and $150 for the whole assembly so I am going to try a custom, but fairly simple fix. I'll let you know how it works out. If so, I will try to post some pics. Kevin

 

[medmo54]

I had a very similar issue with mine as well -- ended up being a bunch of broken wires in the drivers side door where they go from the cab into the door. My dome lights wouldn't shut off, door ajar light came off and on even with all doors/hatches closed, but no audible alarm unless a door was actually open.

If you haven't found a fix yet maybe be worth pulling the rubber boot back between the cab and door and checking for any damaged wires. When I pulled mine back I found 5 wires that were all but broke and 3-4 others that weren't far from it. I ended up removing the harness from the door and taking the door off (pretty quick job actually) -- reconnect all wires and tape up each of them seperately -- haven't had a problem since.

 

[severtecher]

Ajar buzzer fixed

Got no pics, but I did fix it without new parts.
I removed the latch assy. from the rear glass hatch, put a .015" shim instead of the .030" rubber washer under the switch. Then I reinstalled the switch but did not twist it the full half turn or so. I stopped short of that where it felt solidly mounted and cemented the switch in place. I let the assy. dry overnight, then reinstalled the assembly. Drove the car for a day and reinstalled the plastic. Works fine now, no bumps too big.
This is not something a shop would do because of warranty issues and it takes a bit more time than just installing a whole new $150 latch assembly.

 

[cwoernle]

Thanks, medmo54 and severtecher. Good advice from both of you.

 

[AllisonL]

I can send you the steps for testing the Central Security Module, but I need to know if your build date is before or after 03/2002.

-- Rondo

Hi BigRondo,
I have issues with my 03 explorer, door ajar light and its digging when driving and all doors closed, dome light comes on and side mirror lights on the outside come on randomly when parked with all doors closed, security alarm goes off randomly when I lock the doors, and sometimes when driving, my door locks will lock and unlock several times all by themselves. PLEASE HELP!? we already tried wd-40 on all door latches and opening & closing repeatedly, no luck...I'm going bananas nor being able to lock my car, and driving with a flashing dome light with the constant door ajar ding!

 

[mountaineer2004]

this is def fixable:

Interior lights issues

Interior lights do not turn off when I leave the vehicle and shut the doors (even after waiting several minutes). Instead I have to manually turn the wheel on the dash just left of the steering wheel all the way downward to get the interior lights to turn off. Any advice? 2004 Mercury...

www.explorerforum.com

I had same problem. Fixed it by pig tailing sensor wires in all doors except driver door and rear main hatch door.
If you have children (mine all grown), you may want to replace all defective door assembly actuators to maintain function.