I am currently working on my driver side window. It has not moved since I bought the car, it didnt even have a window/mirror switch wired in originally.
The previous owner took the car to the dealership to have it diagnosed. They told him that it was a door control module.
I decided to do my own digging.

Now, someone had said "**** it" at some point and decided to bypass the entire control module and just run 12v power directly to the motor and install a switch inline.




So truly it seems the worst gremlins are in fact the previous owners and the dealership they had work on it.

Now, back to the task at hand. I removed this black and pink addition to my wiring harness and ran 12v to the window motor directly and it runs up and down at full speed with no issues whatsoever.

I then tested to see if i was getting any voltage out of those wires from the door control module. Nothing.
I happened to order a replacement door control module that the seller claimed was tested working. It still has a sticker from the last place that it was repaired from on the case. Neat.

I pulled out the door control module and replaced it with the donor control module from a 01 convertible. Now I have power in both polarities on those wires coming from the control module.


I think, HEY, all i have to do is connect these wires and I should have a working window! Not so fast!
Now when I hit the window up down switches, instead of just hearing relays clicking, I also hear the window motor whine for a very brief moment. Unfortunately, no movement accompanies that whine. It also seems as though when I hit the window switch, the door lock makes a clicking noise, not sure if it is a relay or what it is, but it comes from the latch area on the inside of the door.

I thought, hey, maybe i got a door control module that is incompatible with my vehicle. Let me see if I can open up the old one and see if there is anything visibly wrong with it that I can repair.



Pretty easy to see the burnt up trace here. I figured that I would give it a crack at soldering a wire between the posts that the traces is supposed to connect. Maybe I could get my window working again today afterall!




This is about the time that fate stepped in to remind me, hey, you are really bad at soldering. In the end I did manage to get a connection between the two posts, regardless of how ugly it is.

I reinstalled this door module back in the car, and now I get 12v on the window motor wires where it previously had nothing with this module.
Unfortunately, now I have the exact same behavior from both of the door control modules.

This leads me to believe that something else is at play here. Especially that I am receiving 12v on the motor wires but getting no movement. It almost acts like it just doesn't have enough current flowing through those wires to move the motor.


Anyone else that is good with electronics want to help decipher why this may be acting the way that it is?

I have had this problem before when I was running too thin ( or long ) of wires to power a load. This tidbit leads me to believe that maybe i have a broken power or ground wire leading to the control module, making it so it has enough current to power the module, but not operate any heavier loads?

 

Probably not much help but a bit of lateral thinking for you. Have you tried the passengers side module on the drivers door? If that works at least you know its the module. You could even try your new modded one on the passengers side too?

Just a thought

 

So, funny story. Both of the doors have been vandalized in this manner. And I don't have room where the car is sitting to get both doors open and panels off without slamming the doors against my 74 XJ6. So I am just tackling the driver door at the moment and then will be debugging the passenger door afterwards. It doesn't have a switch wired in either, and i believe i saw that it also has had the window motor wires cut in half as well.



SO.

I just managed to fix the driver door window. I remembered that when I purchased the driver door power window switch connector from a Jag forum member, they sent me the whole driver door harness in addition to just that one connector.
I pried the door jamb harness connector off ( i got a few new blisters on my fingers in the process of this ). In the end the only way i was able to get this connector off was with a strap wrench. If i had used it earlier i would have spared my fingers as well

Once i connected up the harness sold to me by CyJag, the window moved up and down effortlessly with the switch.

I suspect that water got into the door at some time and I will find that the wiring harness between the door jamb and the door control module is corroded. I imagine that these wires were not capable of passing much current through them, although it seemed that they were getting better with use as one by one things in the door started working better. At first not a single thing in the door worked, then the puddle light turned on, then the door microswitch started working, then the power door locks kicked back on, and then finally the connection to the can bus to tell the interior lights to shut off started working properly. All of this over the span of a month. I highly doubt that the wires would have ever started working well enough to pass enough current to power the window motors however.


Now on to repair the passenger side, which I expect is likely more of the same.

 

Mad Hatter,

Well done on the driver's door. Don't you just hate it when you find a previous owner's "bodge/hack" job!

Don't worry. Blisters will heal. Just don't lose a finger if the window comes down! Be safe in that confined space.

 

I undid the battery cables about 15 times while working on this. Even then i was shocked at how fast the window moves when it finally did. If i had my hand in that door i likely would be missing some digits about now.