Hi All,

Hoping for some guidance.

My Fiesta's front electric windows has recently started to act strange. While opening or closing, they would just stop working completely. Both windows have the same symptoms.

No noise, movement at all.

They only start working again if I disconnect and recoonect the battery, and it only lasts a few hours until they do the same again.

I have replaced the driver door switch module, the control module in the driver's door and even the BCM, and the problem still persists. Even removed the window glass and lubricate the guides.

Using ForScan, I can see the switch signal reaches the BCM, but the windows wont move.

Thanks in advance

(2013 MK7.5 1.25L)

 

Is your Fiesta a 3 door or a 5 door model ?

If it's a 5 door model does it have electric windows on the rear doors ?

Hi,

It's a 5 Door Model with no power windows at the rear.

Did some more tests this morning and found the following:

1. The issue persists evene when I disconnect the window motor (driver door)

2. When I disconnect the motor, I can still hear the relay activating, but after a while the relay starts acting strange and become non responisve, but this happens with my new door control unit as well, so the problem sits higher up in the process.

Thanks

Quick question, what is the battery terminal voltage measured with a multimeter ?

12.35V

I initially thought it might be a battery problem, so I replaced the battery a few weeks ago, but did not fix the issue.

Given that you have replaced all the modules and switches involved, and very importantly it affects both front windows at the same time (if I understand correctly), then there can be only one place that the fault can be.

I suspect that you either have a broken/corroded wire or that fuse F6 (10Amp) in the passenger fusebox is loose and not making a good contact.

Look at the attached circuit. When that wire looses power (connector 659 pin 1 of the Drivers Door Module) both windows will stop working.

Will check and provide feedback.

Thanks for the quick responses, you are a legend 😎

Just gone out to check and the F6 does not have an impact on the windows, they still open and close after pulling the fuse.

I then pulled all of the fuses 1 by 1 and found that the F15 fuse cuts the circuit to the windows.

And I might just clarify, the issue is not always simutainiuos between the 2 windows. Sometimes only 1 stops working, then the other, then one might start to work again while the other is still stuck, so they seem to fail independant from one another. But after disconnecting the battery, both works fine for a while. I might add that it seems to be worse when it's cold outside and raining, so I definitely suspect some water ingress and possibly a corroded cable as you mentioned.

On 2/10/2024 at 7:16 PM, DjvanRooy said:

I have replaced the driver door switch module, the control module in the driver's door and even the BCM, and the problem still persists.

Normally I'd say without hesitation that the fault is with the BCM, but you say that has already been replaced so that would rule that out.

Fuse 15 in the handbook is fuse 6 on the wiring schematics, Ford just like to mix things up for fun.

I'll take another look at the circuit diagram. Interesting that both windows have the same fault but that it can happen at different times.

 

Ah okay, makes sense.

Yes it's really strange, and sometimes they start working again after a while, but most of the times I either need to disconnect the battery, or pull F28 (or F27, can't remember now) to get them working again.

Thanks, will also do some more wire checking this week and post any updates.

Well after looking at the schematics again I can see so single point that could cause a fault with both windows but at different or the same times.

After you fitted the replacement Body Control Module did you download and install the 'AsBuilt' data for your car from the Ford site with FORScan ?

I did not. I extracted and saved the .cct and .abt files from my current BCM and reapplied it to the new one.

Would it be worth downloading and applying the AsBuilt ones?

It was just a thought that the files might have a 'glitch' in them and perhaps worth downloading the AsBuilt files. If things don't work out, at least you have the saved files from your original BCM.

I'll give that a try, thanks.

Whats the best place to find the AsBuilt files? I've found https://www.motorcraftservice.com/AsBuilt, is that fine?

Yes that site will do. Or just use FORScan and click on the AB Button at the bottom of the screen.

I bet you have a broken or breaking wire in the door harness to body harness connector

1 hour ago, DaveT70 said:

I bet you have a broken or breaking wire in the door harness to body harness connector

Hi Dave, will definitely check this as well.

Do you have any recommendations on the best way to test this using a multi-meter?

Thanks

15 minutes ago, DjvanRooy said:

Hi Dave, will definitely check this as well.

Do you have any recommendations on the best way to test this using a multi-meter?

Thanks

Resistance from pin on door connector to window lift motor

On 2/12/2024 at 1:59 PM, DaveT70 said:

Resistance from pin on door connector to window lift motor

Hi Dave,

I checked the connection between the door and the body and there has definitely been some water ingress.

There are also some signs of oxidation on the pins.

Thinking of replacing the entire harness, do you know if the 3 door and 5 door has the same harness for the driver door?

 

 

On 2/16/2024 at 12:16 PM, DjvanRooy said:

Hi Dave,

I checked the connection between the door and the body and there has definitely been some water ingress.

There are also some signs of oxidation on the pins.

Thinking of replacing the entire harness, do you know if the 3 door and 5 door has the same harness for the driver door?

 

 

No buddy, three door is longer

Hi.

So I figured out the issue....

When I bought the car, the external temperature sensor was missing and the caused the red ice warning to appear on the dashboard.

I sourced a new temperature sensor and installed, but it seems like it was providing the Fahrenheit reading instead of the Celsius reading, although the car still 'thought' it was Celsius.

This did not bother me much since the red ice warning was now gone.

At one stage I realised that the windows issue started when I installed the new sensor, so I took the sensor out, reconnected the battery and never had then window issue again!

Bought another temperature sensor, but sill showed Fahrenheit, so I gave up on fixing that issue, at least the windows issue is sorted.

I wonder if there is some sort of overheat setting that stopped the windows seeing as the external temp was reading as +- 80 degrees Celsius?

Nevertheless, issue solved.

 

8 hours ago, DjvanRooy said:

So I figured out the issue....

Well that was a quick fix, it only took 8 months 🤣