Technical Electric window drivers side

[tjr]

Hello,
First posting after much lurking...

My daughter is getting her license this spring, and wanted a barchetta as her first car(!). We found her a Green -95 with several of the common barchetta/Fiat issues to sort out... First one:

The drivers side electric window is all the way up but won't come down not even with me putting a little weight on it to motivate movement.

Passengers side window works fine. Electric mirror works fine on the passengers side, on the driver's side it initially only moved left and right, but after minimal exercise of the "mirror choice"-button, now also up and down.

When trying to operate the drivers side window; you can hear a click from I'm guessing the window ECU (under the glove compartment), and thereafter a click from inside the door, but zero movement of the window, it's not even trying to budge. I tested the current at the electric connector in the door (connecting to the window motor wiring). When the button is clicked, the cable immediately delivers 11.2V (or thereabouts), but then quickly drops down to 0V. , It makes no difference pushing the button up/down, or pressing the button longer/shorter time, it's always the same behaviour.

From my barchetta/Fiat limited knowledge (first one), I'm suspecting the 1) ECU (even though it works for the passenger side), 2) some type of (overload) sensor in the door, and/or 3) the motor.

Am I missing something? Anyone wanting to share some experience, suggestions on the suspected culprit and arguments as to why?
Thanks in advance and for your time!
Thomas

 

[turining]

Hello,
First posting after much lurking...

My daughter is getting her license this spring, and wanted a barchetta as her first car(!). We found her a Green -95 with several of the common barchetta/Fiat issues to sort out... First one:

The drivers side electric window is all the way up but won't come down not even with me putting a little weight on it to motivate movement.

Passengers side window works fine. Electric mirror works fine on the passengers side, on the driver's side it initially only moved left and right, but after minimal exercise of the "mirror choice"-button, now also up and down.

When trying to operate the drivers side window; you can hear a click from I'm guessing the window ECU (under the glove compartment), and thereafter a click from inside the door, but zero movement of the window, it's not even trying to budge. I tested the current at the electric connector in the door (connecting to the window motor wiring). When the button is clicked, the cable immediately delivers 11.2V (or thereabouts), but then quickly drops down to 0V. , It makes no difference pushing the button up/down, or pressing the button longer/shorter time, it's always the same behaviour.

From my barchetta/Fiat limited knowledge (first one), I'm suspecting the 1) ECU (even though it works for the passenger side), 2) some type of (overload) sensor in the door, and/or 3) the motor.

Am I missing something? Anyone wanting to share some experience, suggestions on the suspected culprit and arguments as to why?
Thanks in advance and for your time!
Thomas

You say you tested the current - if you had that would give you some more evidence eg short circuit, but you measured the voltage and generally I've found that if the voltage drops to zero it's a bad contact. At least that is where I'd start. Maybe the fuse connections or the relay.
Could be wrong of course.

Best of luck.

 

[tjr]

You say you tested the current - if you had that would give you some more evidence eg short circuit, but you measured the voltage and generally I've found that if the voltage drops to zero it's a bad contact. At least that is where I'd start. Maybe the fuse connections or the relay.
Could be wrong of course.

Best of luck.

Thank you kindly for your response!
Ok, before randomly ordering parts I’ll spend some more time going over the wiring checking for shorts and bad contact. I did pull out and inspect the fuses and relay/window-ECU plus put a little copper grease on the contacts. There were no obvious issues (oxidation from eg moisture).

 

[tjr]

Thank you kindly for your response!
Ok, before randomly ordering parts I’ll spend some more time going over the wiring checking for shorts and bad contact. I did pull out and inspect the fuses and relay/window-ECU plus put a little copper grease on the contacts. There were no obvious issues (oxidation from eg moisture).

I wonder how the electric currents go when ok on the drivers side. My faulty one sends out 11.2V and quickly drops to zero. This behavior will repeat itself every time the button is pressed. In my mind it seems something is working, the button is pressed and current is sent. Then for some reason the current is turned off. If the system worked properly, I suppose the window-ECU (wECU) would send 11.2 or 12V continuously until the window was down. If the wECU was faulty no current would be sent. Now if the wECU gets a signal back that there is no movement; “When the frequency falls below the specified threshold (15+/-5 Hz) the “NOISE DETECTOR” (frequency detector) cuts off the supply.” from the Service Manual, 55 - Electrical system, Fault disgnosis(!) p. 39.
I’m thinking the wECU is doing its job, and it’s a mechanical fault of a non-working motor or an obstructed window. As the there is zero movement of the window and no straining of the motor, I’m guessing on a seized motor. How’s my logic holding up? What am I missing??

 

[tjr]

I wonder how the electric currents go when ok on the drivers side. My faulty one sends out 11.2V and quickly drops to zero. This behavior will repeat itself every time the button is pressed. In my mind it seems something is working, the button is pressed and current is sent. Then for some reason the current is turned off. If the system worked properly, I suppose the window-ECU (wECU) would send 11.2 or 12V continuously until the window was down. If the wECU was faulty no current would be sent. Now if the wECU gets a signal back that there is no movement; “When the frequency falls below the specified threshold (15+/-5 Hz) the “NOISE DETECTOR” (frequency detector) cuts off the supply.” from the Service Manual, 55 - Electrical system, Fault disgnosis(!) p. 39.
I’m thinking the wECU is doing its job, and it’s a mechanical fault of a non-working motor or an obstructed window. As the there is zero movement of the window and no straining of the motor, I’m guessing on a seized motor. How’s my logic holding up? What am I missing??

Update:
Well I learnt it was easy to separate the motor from rest of the assembly (another thread, this forum), so I tried it out. It was a piece of cake, two short Phillips screws and the motor was out. I tested the windows button and the motor performed as intended. An additional benefit was that I now had the possibility to run the window assembly up and down. It catches in mainly two “spots” going up and down. My guess is that the cable has frayed and catches in tight turns. Next step is to disconnect the window and tear out the cable assembly.

 

[tjr]

Update 2:
I found the cause, solved it (I thought), re-installed the assembly and the problem is back (to some extent)...!
I have no idea if this assembly is original or aftermarket, neither do I know if the cable has been replaced, but here is the deal:

I pulled out the cable assembly and I couldn't see any frayed wire. The sound originated(s) from the power window "gearbox" (see picture). I opened it up and found that one of the cables had jumped out of its track and was interfering with the other. So I:
cleared out the old dry grease
sorted the cables out
reassembled the assembly
re-greased it all
and tested it outside the door, it slid like a dream completely noise-free!

Success!!

I installed the assembly in the door and almost immediately the noise /cable interference was back, but still works. I haven't installed the window as of yet, so I'm not sure if the assembly will work with the window. Even if it would continue to work, for how long? Besides the noise is pretty disturbing.

Any ideas what is causing this?
The cable is dia 2mm, how does that fit with original?
Is there too much cable wound on the white cable holder on the pic?
Is the cable too tight (or too slack)?
I found two possible cable adjustment points plus the system in the upper right corner of the enclosed photo. What does it do? It is spring loaded, and is showing some wear and tear.

 

[tjr]

Update 3:
I kindly received feedback from Panagiotis Boudaniotis via YouTube that the mission of the spring loaded contraption is to adjust the wire tension, but in my case time has taken its toll on the plastic teeth. In the picture below you can see how the teeth are supposed to look like on the first two rows from the left as compared to the ones thereafter.

My theory is that the flexibility, because of the tooth degradation, has become too generous, and the wire inside the "gearbox" with too much slack leaves its track and jumps up over its neighbouring wire (moving in the opposite direction) causing noise and high friction. At worst this results in a jammed window. With Murphy's law that will be in rain, sleet, snow or all of it at once.

Buying a new window driver assembly will fully sort this problem out, but having to buy new everything (€413 for the drivers side) just because a small plastic thing worth €1 has worn out bugs me, not to speak of the environmental aspect. My solution, that should at best be temporary, involves two cable ties, please see picture below:

At first I sorted the bungled wires out in the "gearbox" and thereafter ran the window driver assembly (without the cable ties). Already after the first run, the noise was back and thereafter the driver started getting obstructed. I could see how the wire tension adjustor was moving both left and right depending on if the driver was moving up or down.

After adding the cable ties the wire tension adjustor's movement to the left has been arrested, it can only move to the right (becoming tighter). Since then the driver "gearbox" problem has not re-appeared during a handful of test runs. My main concern is if the cable ties will be pushed out of position by the rather violent jolts from the window driver. I'll run the driver some more, and then I might attempt to glue the cable ties in position, before attempting to re-install the driver.

 

[tjr]

Update 4:
I decided to chance it and see how long my hack might work.

I did alter the setup somewhat by replacing the one larger cable tie (on the left cable side) with three smaller ones. First I filed down the broken teeth to hopefully get a more snug fit. The remaining teeth in good condition should also offer some support. After tightening up the three cable ties I added some hot glue for shock absorption and hoping it might assist in keeping the cable ties in place. After running the window driver assembly some more out of the door without noise and/or jamming, I re-installed it in the door including attaching the window. It works fine so far...

OT (window leak/noise reduction?):
I added a 1,7mm washer on each of the two lower window assembly door attachments as done in https://www.youtube.com/watch?v=-IGZDXtLKNc&t=509s @ 18:05 and 19:20 (the narrator explains in Italian, but speaks English with the older gentleman (Dutch?) actually doing the work). To my understanding this would move the window assembly out on the bottom part thus moving the window further into the soft-top gasket liner as compared to original. Before fitting the window I retracted the two "A" adjusters.
Just as shown in the video, my window now goes under the very top rubber lip of the gasket on the windshield "frame" (next to where the soft top attaches to the windshield "frame"), which it did not do before. This is without adjusting the "A" any more than just touching the window. I have no idea how this modification will affect the window to gasket seal lower down, but time will tell.

Let me know if you tried any of the above and how it worked for you.

 

[tjr]

Update 5:
Fwiw; plus one year on, the "wire tension adjustor"-hack is still doing its job without (known) problems.