Stupid Rear Power Window Problem

mzbhavn

New Member
Dec 28, 2005
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2001 Cobra Vert.

My rear passenger window will not activate unless I have the driver's door wide open. I probably have a broken wire in the harness between the window switch (on the driver's door) and the other end of the harness (wherever it goes). I can move the harness in the door jam to activate or deactivate the power to the rear passenger window so it kind of pinpoints where the problem is. Since this Mustang is a convertible I don't have rear window switches, so I need to rely on the "Master" switch on the driver's door. I checked the "Master" switch to make sure that all of the wires were fully inserted and stable.

I'm fairly sure that the problem is in the harness between the door and the body but I'm not totally certain. To get to the harness should I remove all of the door trim, kick panel and/or ...? I really don't want to split the rubber shield that is in the door jam to only find out that the broken wire is not at that location. And if I do cut the rubber shield what should I use as a replacement?

What is the best way to tackle this problem? I would like to put the top down sometimes during the good weather but I don't know if I can ever get the rear window up again. What a stupid problem to have and the FSM was of no help.

TIA - Mark
 
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Funny thing. I have also encountered a problem with a passenger window that would not go up on a 2005 F150. The problem went on for two years. We knew from testing there was a break in the wiring harness but my Son and I were not able to find it. I was unwilling to take the dash out for this problem.

I'm a big believer in Occam's razor.

https://en.wikipedia.org/wiki/Occam's_razor

Occam's razor would tend to say the problem just HAD to be in the wiring between the door and the body frame since that's were the wring bends every time the door is opened. To make a long story shorter we found the wiring break in the door to body area. It turns out the break was in the body area where in all of the previous cases I had looked in the door area.

Moral of the story? Pull the door protector boot back from BOTH sides. The break was such that it didn't take fancy test gear to find other than a "Mark I eyeball" and perseverance (more than I had the first time).

Regarding the wiring diagrams not being of any help. Perhaps it's the way they are being used? I just have a feeling that if you were to place a Volt-Ohm meter (VOM) in continuity mode (where it beeps) between the wire in question this would let you know when the path is complete and when it's not. Then start by perform a "wiggle" test up/down the length of the wiring harness. Often times when you get near the area of the break the connection will come and go. Thus letting you know when you are getting closer.

Wiring harness faults can be some of the most difficult problems to track down. Good luck.
 
I did an F150 lately....was able to take the rubber boot out of both ends and push it into the door opening enough to allow room to solder the wires. It is a tight fit but I would try it.

Funny thing. I have also encountered a problem with a passenger window that would not go up on a 2005 F150. The problem went on for two years. We knew from testing there was a break in the wiring harness but my Son and I were not able to find it. I was unwilling to take the dash out for this problem.

I'm a big believer in Occam's razor.

https://en.wikipedia.org/wiki/Occam's_razor

Occam's razor would tend to say the problem just HAD to be in the wiring between the door and the body frame since that's were the wring bends every time the door is opened. To make a long story shorter we found the wiring break in the door to body area. It turns out the break was in the body area where in all of the previous cases I had looked in the door area.

Moral of the story? Pull the door protector boot back from BOTH sides. The break was such that it didn't take fancy test gear to find other than a "Mark I eyeball" and perseverance (more than I had the first time).

Regarding the wiring diagrams not being of any help. Perhaps it's the way they are being used? I just have a feeling that if you were to place a Volt-Ohm meter (VOM) in continuity mode (where it beeps) between the wire in question this would let you know when the path is complete and when it's not. Then start by perform a "wiggle" test up/down the length of the wiring harness. Often times when you get near the area of the break the connection will come and go. Thus letting you know when you are getting closer.

Wiring harness faults can be some of the most difficult problems to track down. Good luck.

Well, I personally want to thank both of you. You both were a huge help.

Occam's razor is still working. That was quite an enlightenment reading the link you posted. However, after reading it I think I would have rather read a book by Nietzsche cover to cover (jk). At least I learned something today.

Silly me, of course the most probable place for a break was where the wires bend most often. There's not much room to work in and I had only about 1 1/2" on one end (near the door end of the harness). Pushing the boot back into the door helped a lot. I had to finagle some wire ties to help pull the harness out some more and toward me. Butt splicing with some solder was probably the most difficult while trying to get a good tin on the stranded wires. A little heat shrink and some electrician's tape should help hold the splice together and two wraps of the tape around the whole harness where the break was might help with any stress put on my pretty crappy splice job.

The FSM showed me what wires to look for. My FSM is one of the Ford Service Manuals that are on a CD or DVD. In the wiring section, one should be able to find the harness on the vehicle and furthermore be able to locate the connector / splice. Then it should advance you a section that describes how to access the connector / splice. I'm a little obtuse in trying to figure out how to navigate this piece of software. That was the reason for my little rant about the FSM. It was really my fault, not the service manual. Now that I might have a little free time, maybe I can wrap my head around the FSM software.

Anyway, thank you both for your assistance. I really appreciate it.
 
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Thanks for the reply. Sometimes answering forum posts seems like a thankless job as few people seem to acknowledge any help they get.

I understand the pain of doing the splice. In my case I figured the wire broke because it was too tight. Each time the door closed the wire was pulled across the opening. I could see that the wires that broke were actually shorter than the rest of the wires in the bundle.

Therefore a butt style splice would likely fail again since this would shorten the wire even more. So in my case I chose to splice in a short piece of wire that was long enough to form a small loop back onto the wiring harness. Instead of twisting the wires together end to end, I did it "pig tail" style. The thought process was to get the solder joint away from the bending location and thus make a longer lasting repair.

But as you have learned that finding the wiring harness fault was 3/4 of the job. The repair was relatively straight forward after that.

Good luck.
 
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Thanks for the reply. Sometimes answering forum posts seems like a thankless job as few people seem to acknowledge any help they get.

I understand the pain of doing the splice. In my case I figured the wire broke because it was too tight. Each time the door closed the wire was pulled across the opening. I could see that the wires that broke were actually shorter than the rest of the wires in the bundle.

Therefore a butt style splice would likely fail again since this would shorten the wire even more. So in my case I chose to splice in a short piece of wire that was long enough to form a small loop back onto the wiring harness. Instead of twisting the wires together end to end, I did it "pig tail" style. The thought process was to get the solder joint away from the bending location and thus make a longer lasting repair.

But as you have learned that finding the wiring harness fault was 3/4 of the job. The repair was relatively straight forward after that.

Good luck.

My parents (along with other advice) told me to always be polite but my response to you was totally reactive. Sometimes being polite pays off. Also, when I was working, a little bit of brown nosing worked wonders.

Since I had so little wire length to work with I tried to run a new wire from the door - body area to the switch. Well, that was a fail. I would need to remove the door trim to snake the wire back up. I also thought, as you suggested, putting in a small length of new wire between the two broken wires. It looked like I had enough slack to work with what I have so that is why I ended up doing a butt splice. Maybe I underestimated the lengths and stress on the harness but if (and when) my splice fails I'll add an additional piece of stranded wire between the two broken ends like you have suggested.

Again, thanks for your help and enlightenment.