The Dreaded Drivers Door Module Part Numbers

Just so you know I'm not a flake, my Bluetooth obd adaptor was being flakey with my laptop so no ddm data from my car. I ordered a usb one off amazon, should be here Monday and I'll get back to it. Amusingly when I did get it to connect I could a couple of new codes I'd rather have not seen lol....
 
I was able to trace out two of the four LG/VT wires that go into the 4 into 7 splice in the door today. Sure enough, one of them goes to the power trunk module and one goes to the passenger side door lock switch, per my hunch posted above.

So, one of the other two will be to the driver's seat module and the other one will be the dead hot lead from C238. I haven't figured out how to tell which one goes to the seat, since there is no shot at all of getting to the seat connector right now, the seat is too far forward. Maybe probe across each of those two while probing the seat control connector with my ohmmeter? If I see any resistance other than infinity, that should be the resistance across some component in the seat module.

The other option is to hook everything else back up and then probe each of the two remaining LG/VTs with a hot jumper while working the seat controls. I think this is a little risky though since I don't know where that voltage is going for the dead wire.

In short though, this sort of illogical location for these splices has greatly simplified the wiring plan I posted above. All I need to do now is bypass C238 completely with one wire out to the door, then splice everything together in one place.
 
The download screen for my As Built file was one of my earlier posts. Thanks tho'!
 
OK, folks, here's the conclusion you were all no doubt waiting for with baited breath. ;)

  1. Every splice on the wiring diagram I posted above is indeed right there in the door, except for the splice that goes to the adjustable pedal switch up in the dash. It is prior to C238.
  2. At some point after C238, the LG/VT wire was, as best I can describe it, rotted. The insulation was fully intact all the way to the splices, but when I went to bend that wire out of the way, it just broke. Then I tugged on what was left after the break, and it snapped off too. The copper was very brittle, and the insulation was too. Not like it overheated and melted, but overheating is the only option I can see as to why it did this. The resistance from this wire to C238 was in the Mega Ohm range.
  3. One factor in the wire's demise may have been that the conduit it was in allowed water to get in and accumulate. It was coming in through the speaker wire, which enters the conduit almost vertically (black wrapped cable coming down vertically in 1st pic), and there was water accumulation evidence inside the conduit, 2nd pic below, and this was after I cleaned out a good bit of the grit you can see. The white wire is the new wire that I wrapped around the harness, connected to the upstream side of C238. I made my cut prior to C238, so the downstream side is now cold. You can also see that I had traced out the power trunk ("T") and passenger side power door lock ("PDL") wires and had labelled them.
  4. To prevent future water intrusion, I heavily taped the harness back past where I had cut it open (the conduit itself is wrapped in black tape at the factory), and then because I'm a belt and suspenders kinda guy, I sealed off the entry of the speaker cable even more with Permagum (duct sealant) and another cap of tape over the top of that. This is the third pic, though I had not put the tape cap on top of the Permagum yet.
So, all that to say, everything works now - seat, mirrors, power trunk, locks, remotes, everything! I will probably get around to creating a separate post documenting all of this for others struggling with DDM issues.


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Here is a puzzler for you all. My fathers 2010 Town Car has developed a weird glitch.
When he starts the car, the trunk opens, When he turns the car off and restarts it, the trunk closes.
Same thing happens every time.
What I have read so far seems to point to the DDM.
Has any one else experienced this glitch and am I on the right track?
Thanks all.
Les
 
You probably should start a new thread for this...

First step is to test the battery. The DDM might glitch on the voltage dip during starting and respond by pulsing the trunk signal. It's weird but...
 
Vinci said:
The download screen for my As Built file was one of my earlier posts. Thanks tho'!
Click to expand...

I still haven't got back out to mine, been a crazy week with broken old cars galore.
 
LesRoss said:
Here is a puzzler for you all. My fathers 2010 Town Car has developed a weird glitch.
When he starts the car, the trunk opens, When he turns the car off and restarts it, the trunk closes.
Same thing happens every time.
What I have read so far seems to point to the DDM.
Has any one else experienced this glitch and am I on the right track?
Thanks all.
Les
Click to expand...
I'm no mechanic, but I've been on a couple Town Car forums for 8 years and never heard of that one before!
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Vinci said:
OK, folks, here's the conclusion you were all no doubt waiting for with baited breath. ;)


  1. To prevent future water intrusion, I heavily taped the harness back past where I had cut it open (the conduit itself is wrapped in black tape at the factory), and then because I'm a belt and suspenders kinda guy, I sealed off the entry of the speaker cable even more with Permagum (duct sealant) and another cap of tape over the top of that. This is the third pic, though I had not put the tape cap on top of the Permagum yet.
Click to expand...
I would follow that up with some other low tech maintenance.
RainX (or equivalent) all window glass. This is a surfactant that sheds water off of the glass. The less time water is on the glass the less possibility of water getting inside the door
Wax all metal exterior around the door window glass. (if not the whole car) Again for the same reason. The less time water is on the car the less change of water intrusion into the door.
Lastly if you want to get real retailed, treat the rubber that is in the outside. The piece that rubs against the window glass. Run the glass down and get into that rubber. Likely there is debris in the rubber now. That debris or grit has the possibility of scratching the glass at worst case. However, it can allow water past that seal as well.

The above is not a bullet proof solution. However, a layered approach to placing barriers in and around the wiring harness will go a along way in preventing future issues. Some vehicles are exposed to a whole lot of volume of water in some storms. And I understand that is a lot of effort especially as this should be done annually. Contrast that to the amount of labor spent on this repair. And my guess is the waxing is a whole lot easier than chasing wiring issues.

Action
Vinci said:
View attachment 14911
Click to expand...
 
Appreciate the thoughts, but I'm not seeing it. RainX'ing the windows isn't going to change the amount of water hitting the window, it will just change how fast it flows, which if anything might make water intrusion worse. Your doors, and ALL car doors, have drains in them for a reason - because there is no way to make that seal completely waterproof. The main thing that seal is there for is to keep the door from flooding and to keep most of the trash out. I do agree that some attention to the door to window seal is warranted.

The harness from the factory probably had an OK seal where the speaker wire enters it when new. Sometime over 18 years of heat cycling and gravity, the main harness sagged away, opening that seal. I'd bet every Town Car on this forum has the issue to a degree, now that the newest ones are 10-11 years old.
 
LesRoss said:
Here is a puzzler for you all. My fathers 2010 Town Car has developed a weird glitch.
When he starts the car, the trunk opens, When he turns the car off and restarts it, the trunk closes.
Same thing happens every time.
What I have read so far seems to point to the DDM.
Has any one else experienced this glitch and am I on the right track?
Thanks all.
Les
Click to expand...
Les,
Looking at the power diagram I posted on page 4 of this thread, there is a module out in the trunk that controls everything. I'd unplug the connector from it and probe LG/VT wire, which should be hot at all times, and see if the voltage momentarily dips/spikes on startup. It should dip some, but not more than a volt or two IMO. If it does more than that, you're on the way to solving the problem.
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Help support this site so it can continue supporting you!
 
Vinci said:
Appreciate the thoughts, but I'm not seeing it. RainX'ing the windows isn't going to change the amount of water hitting the window, it will just change how fast it flows, which if anything might make water intrusion worse. Your doors, and ALL car doors, have drains in them for a reason - because there is no way to make that seal completely waterproof. The main thing that seal is there for is to keep the door from flooding and to keep most of the trash out. I do agree that some attention to the door to window seal is warranted.
Click to expand...

Those actions will never change the amount of water that contacts the vehicle.
Those actions will definately change how long the water remains incontact with the vehicle. Or how fast the water sheds off of the surface. The less time that the water hangs around on the vehicle the less time the water has to penetrate inside the door.

The vast majority of the water will shed off the vehicle faster with a coating
The rest of the water will be repelled by the coating. Not attracted to the surface of the vehicle to be absorbed and migrate into small openings.

Again these actions will not keep water out of the interior of the door 100%
And I agree the door seals are rarely water tight throughout the life of a vehicle.
There are door drains in every car. But by the time the water gets to the door drain it is too late. Wate inside of the door has a shot at getting inside of wiring or contacting the window regulator or other pieces. Taking action to put a coating in the exterior of the door only adds another barrier or obstical for water intrusion. And further limits water intrusion.

For the water that got into that harness, if the amount of water was cut in half over the life of the ownership, you might not have had that repair to do. Even with that speaker wire opening in the harness. Your repair will fix that. And keeping as much water out of the inside of the door in the first place will help as well.

Action
 
Vinci said:
Les,
Looking at the power diagram I posted on page 4 of this thread, there is a module out in the trunk that controls everything. I'd unplug the connector from it and probe LG/VT wire, which should be hot at all times, and see if the voltage momentarily dips/spikes on startup. It should dip some, but not more than a volt or two IMO. If it does more than that, you're on the way to solving the problem.
Click to expand...
Thanks so much for answering. I haven't interacted with forums much.
I assume you mean "Power Luggage Compartment Lid Module".

From what you say, I would assume the module is looking for a power dip to trigger a cycle.
If that is correct, should I see a dip if the Compartment Lid button on the door is pressed?
And does "LG/VT" mean a light green wire with a violet stripe?
Also, not to be too needy, but where in the trunk might I look for this module?

Les
 
After a closer look at the provided diagram, I see a lot of "LG/VT", So that is probably not a color notation.
 
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