Your solution would seem to imply that the wire going to the passenger door had a short in it. What doesn't make sense is that then the chime should be ringing to indicate it thinks the passenger door is open.

Mine doesn't chime, even though it appears the GEM module thinks the passenger door is open because the only chime I get is when the driver's door is opened up.

To me that would indicate then that this problem is being caused by a faulty GEM module in my case. Otherwise why no ding with the door ajar light always on?

Unless somebody can point to another possible issue without it being the GEM, I think I'll just put black tape over the light and live with it. I've already hot glued a battery powered $3 touch light to the ceiling since I've got the fuse and lights yoked from the stock dome light with it never turning off.

Does anybody know of a quick and dirty way to just disengage the ajar light short of putting black tape over it? If I had a schematic for this GEM/doors/dome interaction I could troubleshoot it for further potential solutions.

 

I have the same truck that you have with the same problem. I have not yet begun to troubleshoot it yet though. I will be working on it over the next couple of days and will post my findings in here when I get it fixed.

It appears to me though that you're hung up on the wrong point here - your passenger door. Think about it man - your passenger door gets WAY less use than the driver's door does. The likelihood of the problem being in the passenger door mechanism is far less than the driver's side. You're barkin up the wrong tree I suspect.

 

Those also having problems other than the door ajar light switches, that are controlled through the GEM, should add it to their suspect list. If your scantool won't scan the GEM for trouble codes, which could help in deciding on what best to check next/move higher up on your suspect list, maybe consider investing in an inexpensive ELM scantool & using the freeware FORScan, that can access & scan the GEM for those trouble shooting code clues, as well as other vehicle controllers/computers.

I opted for this one https://www.ford-trucks.com/forums/1...-scantool.html, to scan my GEM for ABS trouble codes back in Dec 2013 & it also found GEM stored body codes that I didn't know I had, that have provided clues as to why my passenger & now drivers side power windows are intermittent. The ELM can be had shipped, for around $25. I saved more than that by not having to pay a brake shop to scan for ABS codes!!!!

 

Welp, the WD-40 in the door latch trick did not work for me - as I figured it wouldn't. So far nothing has been 'easy' on this truck. And during the process of all the oiling and door-slamming, the linkage to the bottom latch on the right rear cab door came off and now I can't get that door opened. (Its an extra cab with 4 doors)

I'll have to wait a few days - until I get over wanting to punch a baby before I can continue this troubleshooting effort.

 

Back when I first got this truck 4 years or whatever ago, I suspected the door ajar light was being caused by a faulty door switch, since that's the most obvious thing on vehicles that has caused this for me in the past.

Before doing the usual WD40 flushing of things, figured I'd go right to the source and see if both door switches were working via a continuity meter. Forget if they are supposed to be normaly open or closed when the door is shut. Probably normally closed, but whichever it was they were working properly. Think I even held them in my hand and activated them but they still wouldn't turn off the ajar light, so that eliminates the door mechanism not engaging them.

The odd thing is that while the ajar light and dome light will say on like the door is open, there is no door chime to indicate that, but I still get a chime when I open the driver's door but not the passenger door. This tells me it should be a malfunction in the GEM module and not in the door switches or wiring. If it was a fault in the wiring or switches, there should be a door chime to accompany the dash and dome light being on thinking a door is open.

I read around at the time and saw that many reported faulty GEM modules, and that it was a bad idea to buy one used at the junkyard since they all seemed at high risk for this fault. You have to match them to the right year and Ranger anyway. New ones with the fault corrected can be bought, but they are very expensive at around $150.

Now, things might have changed in the past few years, but that's from memory when reading up on it back then. I have a background in electronics and am a diagnostic repair technician in an electrical/mechanical field, so I may pull that stupid module apart and see if I can find out what the design problem is.

Might even be something as simple as a cold solder joint, which is a common problem among electronics, especially ones in vehicles that are being subjected to vibration. If it's some other component failure, like say a bad relay or resistor on the board, I should be able to swap in a new one. If it's a bad IC then chances are it's not worth the effort.

When I get around to doing this I'll do a youtube video of the repair and post it in this thread.

PS- I've heard conflicting reports on the rear doors having a door switch too. That wouldn't make sense since the back door has to be closed to close the front door, but I guess in this day and age of needless safety features just to sell a few more bells & whistles anything is possible. Also, even if this was the case, then it still won't explain dome light/ajar light being on while there is no door chime. Only get a chime if the driver door is opened. Tells me again it's a GEM fault causing some things to falsely turn on but not others, even if it's being told by the door switches that they are all closed.

I'd like to see a schematic of this whole door/dome light/chime circuit so I can troubleshoot a few more possibilities without having to rip things apart and back engineer the circuit that way. Anybody got one?

 

The rear doors both have door ajar switches. I think your right to suspect the GEM, as the switches just provide ground switching to wake up the appropriate GEM circuit to have it do its thing. The ELM scantool could likely find some trouble code clues that might shed some light on where best to look in the GEM.
A couple years ago I found so many circuit board cold solder joints in my 94 Taurus ecm, that I had to just give up, no way to reflow so many questionable connections. I did reflow the worst looking ones but without joy, just finally gave up & replaced the ecm & that finally fixed the random stall condition I'd spent months tracking back to the ecm, so don't get your hopes up too far on finding something in the GEM, but don't let my experience deter you from giving it a try, you might get lucky.
If you have to replace it, look online at places like RetailMeNot.com for discount codes. I've recently found 30-40% off codes for Advance Auto & used them for the Taurus computer, brakes, lawn battery & the like. Keep us posted on how it goes.

I found a door lock wiring pictorial printed & scanned it, will keep trying to post a picture but for some reason I'm having problems, as check disk says I have a file structuring allocation, or something like that problem, so gotta get that put right before I can post the scanned JPEG picture file, but after looking at it, I believe your problem is internal with the GEM.

 

While I'm thinking about it, remove dash GEM fuse #25, to reset the GEM & see if that'll wake it up!!!! OH, & while its out, make sure it's good!!!!

 

All good information. I also suspect the GEM as my door chime also works as advertised. I am sure the door chime is probably hard-wired into the door switch circuit...where the dome light function probably is not. A lotta newer vehicles have 'fancy' dome light functions...dimming as they go off, timed, tied to the key fob function, etc, etc. None of that kinda stuff ever impressed me. The function of the dome light has never been the deciding factor in whether or not I bought one model of car over another. I'll never understand the philosophies in engineering departments these days. Technology is neat fellas...but simplicity is better sometimes.

 

The reason I suggest putting the GEM high up on the suspect list is that the functions you've posted about are controlled by it, not directly controlled by the door switches. The door switches are used to Wake the GEM up, to do its thing, not to directly control the dome light.

 

Yes - I know that.

What I may do is research exactly what all the GEM does do (or is supposed to do). If I can determine that it only controls the dome light function then I may just wire it out of the loop and rig my dome light to work like they have always worked for about 80 years previous. lol


**EDIT** Wait - I have an idea, I think I'll forget that dumb-assed idea.

 

From our "Tech Info" thread atop the forum, Ken00 posted a nice GEM tutorial on all the things it controls, scroll down to his postings in this thread. https://www.ford-trucks.com/forums/1...m-systems.html

 

Pawpaw, I skimmed over that link about the GEM module's functions quickly here (will read it more closely later) and it appears there might just be another potential issue without it being a bad GEM that is causing the door ajar and dome lights to be on without a chime.

I noticed it says there are certain "alerts" it does or doesn't do based on input from things it monitors. Door open means dome, ajar light, and chime of course. As said, I've got door adjar and dome light but no door chime unless I open the driver's door.

Well, it appears the thing also monitors not only the door switches but the door handles as well. If somebody lifts the door handle the dome light (and I think it said ajar light) will come on for a short span of time. I know these modules are used in other vehicles as well, so does a 2000 Ranger have a door handle monitoring switch? If so, then the solution might be one of those are faulty and that in fact the GEM is fine.

The odd thing is it also says it can monitor the tailgate handle and whether it's open or not, along with heated mirrors and such. I know for sure my Ranger has none of these things, but it might have a door handle circuit since I haven't looked.

I'm going to read that link over more closely along with information about the RAP module it also references that interacts with it. Will keep people updated if I find out anything.

 

My 99 Ranger & 94 Taurus have door handel sensors, as if I raise the handel with the door Locked, so it doesn't open/unlatch, it'll turn the cabin dome light/s on.

 

The wiring pictorial I have but am still having problems posting, show the front & rear door Lock switches going into the GEM Centeral Timer Module (CTM).

The door lock switches feed into the Relay Box, which has All Lock, All unlock & Driver Unlock relays in it & if you have Anti-Theft, those relays & other things also feed into & out of the Remote Anti-Theft Personality (RAP) Module. So the door ajar switches feed into & out of the CTM that controls how long the dome lights stay on when we wake it up by lifting the door handel, or push the remote unlock button & the RAP module decides if its ok to unlock the doors, or needs to sound an alarm/blow horn & flash head lights.

If the dome lights will turn on, but won't time out & turn off, then the GEM CTM belongs on your suspect list.

Have you been having any PATS problems????

 

No problems with PATS, but the fact that there seems to be more things the GEM is sensing then I first thought (without a diagram or short of ripping apart things to back trace them to the GEM) has me thinking the GEM might not be at fault here.

Never go to the extreme without ruling out the simple, so looks like I have more troubleshooting involved. I could just stick with a touch light on the ceiling with the fuse pulled for the dome light to keep it off, along with black tape over the stupid door ajar light, but love the mystery and challenge of troubleshooting, so let's track this one to it's dark end. :') More to follow, but any diagrams of the GEM system and such would be of great help....