So, my Mom has a 2003 Expedition with the 5.4l motor, and about 120,000 miles on it. And lately its been having what I think is computer or electrical or charging system, problems. Its been having problems for a while now, some for a few years, and some are more recent. Here's some of the things that its been doing:

For a few years or so now, I think, it has been showing "Door ajar" on the little screen on the dash, when there really isn't any door open, and it doesn't say which door it is that is open. This has been the main problem that the car is having. It doesn't sound all that bad, but it actually does cause some problems. First off it doesn't automatically lock the doors when you start going like it should. And then the biggest problem that it causes is that it makes all the courtesy lights that would come on when you would open a door, stay on for extended periods of time, once you shut the car off. Sometimes for only a few minutes and sometimes for a half an hour or longer. Most of the time they don't stay on once you start the car but sometimes they do. The main time that they will stay on is after you shut off the car. I'm pretty sure that the lights do stay on longer if you open the doors after the car is shut off, but they stay on way longer than they should, like I said before. What this does is wear down the battery, sometimes to the point where the car won't start, and therefore needs to be jump started. This has happened probably 5-10 times at least. It also burns out the bulbs in the lights, one of the courtesy lights in the passenger side mirror has already burned out, and there will probably be more in the future. This door ajar thing seems to be like sporadic, I guess. Sometimes it happens and others it doesn't. Sometimes it almost seems temperature sensitive, like if there's a big change in temperature it will cause it happen. And then sometimes it will be working perfectly fine and then if you open and close a door it will happen again. So then this will also of course, cause the car to beep twice when you lock it like a door would be open, when none is.

Another thing it does, is have trouble starting sometimes. Sometimes it will have a hard start or have a long crank. And sometimes it will crank once and not start and then have to crank it again to start it, or sometimes even more. So it doesn't really start all to well.

More recently like in the past year or so, it has started to flash "Check Charging System" on the screen. This is also pretty random, it will just happen at random. It will just beep on and off. It will do while driving, just beeping on and off. And then in last few weeks the backup-aid started acting weird. It's done it like 3-4 times. When you put it in reverse the beeping noise of the backup-aid will just go off in a constant tone, when there is nothing behind the car.

So that's pretty much all the problems that we have been having with the car. All them seem to occur pretty randomly, really, with no set pattern or time when they happen, its almost like whenever the car feels like it, is what it seems like. So far I think my Dad's mechanic has looked at, with really no success. And then the battery was replaced probably a few months ago, with a used one, but the used one was in better shape than the past one. So if any of you guys have any idea of what might be causing this, or what might be wrong. I think I said everything that has been going on. Hopefully you guys will be able to help. Any help will be greatly appreciated. Thanks in advance.

 

The door ajar issue is a sticking switch. Spray a liberal amount of WD-40 into the latch mechanism of each door and open and close it several times to work it in. Also do the rear hatch and glass latches.

For the hard starting, it sounds like the fuel pump check valve is starting to fail. The fuel tank has to be dropped to change the fuel pump assembly.

 

Ok, thanks for your response. I will try the WD-40 on the doors tomorrow.

And maybe we'll have to get the fuel pump and check valve looked at sometime. So if it is that then what do you think would cause the "Check Charging System" beep go off and come up on the screen, and the backup-aid alarm to go off like I described?

 

A bad battery or alternator, or a stretched belt can easily cause the charge system message. For the back-up aid, often as sensors fail you will get these messages.

 

2003 Expeditions have a known charging light and beep issue caused by the routing of a small wire harness over an air conditioning metal tube near the right front inner fender. Find that tube and wire, then carefully inspect the wire bundle where it rubs on the metal tube. I found this solution from another site and sure enough it was causing my intermittent charge light and buzzer problem. The wire was worn right through and shorting on that tube.