2003 Explorer Electrical Issues

robert257

So I have a new development in my 2003 Explorer that has me confused. About a week ago I noticed that the door ajar light would remain illuminated and that they radio would continue to play even with the key out of the switch and the door open. Additional the chime that warns you that your headlights are on with the key out no longer chimes meaning that I can walk away with the headlights on and run the battery down. For about two days it also had the curious habit of unlocking itself after I had locked the doors with the button on the door but it would not unlock itself if I used the key in the actual lock mechanism from the outside. That problem disappeared but now the interior light won't come on when you open the door though it will come on manually. As some of these problems seem to be indicative of the car not "knowing" that the door is open (radio playing headlight chime) and some that the door is not closed (the door ajar indicator) and some are just weird (the door unlocking itself), I am wondering if there is some many of ECU that might be the point of intersection for all of these issues or if I am overthinking it entirely.
Any thoughts would be appreciated.

93tracker5spd

Hello! Welcome to Edmunds. It would seem that upon investigation, the problem you are experiencing is a common one for these vehicles. And most of the time it is an easy fix. It is caused by one of two items, either the door alarm switch itself which is rare, or the more common cause is the wire that goes to it, this wire goes through a boot at the door to vehicle attachment point, and flexes each time the door is opened and closed. I have posted below a youtube video of the fix done by a professional who has repaired this condition many times and is showing you exactly how to do it quickly and easily. This pro uses a metal tool to dislodge the boot, I would use a hard plastic trim tool. He is a pro and does this all the time, I would surly slip and scratch something with that metal tool. But he is very good and easy to follow! The other conditions are related to that door alarm and should go away with the repair. If there are no other symptoms, it is not likely that the ECU is at fault, it is simply acting upon the erroneous signal sent to it. Good luck, and let us know how you make out. If upon checking, you find no broken wire, the next step is the switch itself which is located in the lock mechanism.

https://www.youtube.com/watch?v=Vh2r7HrCMRs

thecardoc3

Two comments. The video does a good job of explaining one of the plausible faults for the above reported issue. (The switch itself in the latch is a very common failure) But first, do NOT attempt to do this in place. Remove the kick panel inside the car and the door trim panel so that the entire harness can be accessed by disconnecting the body connector and pulled out of the door. (You can leave most of the internal door connectors attached) The reason to do it this way is that if one wire has broken then all of them are ready to fail so be prepared to add a section of new wire to each wire in the harness. Its much easier to do this once correctly than to have to revisit this over and over again.

The second comment has to do with the trouble light seen in the video. Those tools need the cords cut off of them and thrown away. The incandescent bulbs get very hot and are subject to breakage. There have been serious injuries and deaths when working with fuel tanks etc. that come from the light falling and breaking the bulb and that exposes an ignition source to vapors. Fluorescent lamps and especially the new style LEDs provide much better lighting at a fraction of the cost to use and they eliminate the dangers from those old "drop lights".