Rear electric window regulator - how do they work?

[ianM]

Hi all,

Last weekend, the window regulator in my rear passenger door went kaput - a big "crack" sound came out of it, and once I'd removed the door card, it was easy to see that one of the plastic bits has basically just exploded.

Seeing as I didn't really fancy replacing 20 year old plastic that had just died with some more 20 year old plastic, I got a repair kit off ebay - which is great! The only problem is, I don't really know how the window regulator works, or what it should look like when it's all wired up?

How does the motor know when it's reached the top (or bottom) of the window's travel? Can the motor itself only go a certain distance, or does it rely on sensors? When I re-fit it, do I need to try and make sure the regulator "knows" what level the window's at, or somehow match the window up to the amount the regular thinks it's open?

Beyond that, does anyone have any pictures of how the wires should go? I understand one winds it up and one winds it down, but I just want to be doubly sure I've got it all threaded together properly - and obviously with the old regulator having basically exploded before I got it off, I don't really have anything to compare it to (without getting another door card off, which I really don't fancy)!

Anyone got any experience with doing this themselves?

[vitesse]

I've done a couple of rear door windows, first buying the clips from a VW dealer and then studying pictures of how they should look on eBay ads. A while ago now but I think the clip could only be fitted in the position dictated by the wires, I remember it being a bit fiddly and swearing a bit at the spring which sets the tension. Don't know about the motor, guessing the polarity is switched by a relay perhaps in the BCU.

Regards

[Arctic]

Hi Ian.
I must have at least 6 or 8 sets of rear mechanisms in a bag in the shed which i take to our Nano meets, i can take one out and photo it for you tomorrow if you have not fitted it by then cheers Arctic.

[Arctic]

Ok as promised maybe to late now but the photo may help others in the future.

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Rear window regulators
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Near side to the left. off side to the right, then you have front and rear,
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Arctic

[ianM]

Hi Arctic,

Not too late at all! I'm just about to have a go at it tomorrow, so many many thanks for that! I'm sure I'll be able to figure it out from those pictures!

Many thanks for the advice too, Vitesse. I'm just worried I'll fit it together with the plastic at the opposite end of travel to what it "thinks" it is, then it'll all just twang off and break when I try to use it! Guess I'll just have to have a play tomorrow!

[Arctic]

Hi Ian.
grease the metal track which the plastic runs along, also as i do not know which part as broken did the lit come with new wire? if so you may have to remove the motor from the frame.

To remove the motor and gain access to the wire wheel remove the three torx.
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Lift the frame free.
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The wheel on this regulator was damage due to wire snapping and getting tangled around the wheel, you can see it's damaged the wheel V which the wire winds around.
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Here you can see how the wire fits into the wheel end.
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Here where the wires fits into the side of the wheel.
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The motor can be taken apart also but i doubt you will need to do this.
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I think if it was me having to do this job i would have gone for good known used regulator, it would then be just a case of swapping it out for the old one.

[vitesse]

Great pictures from Arctic (as usual). Just like to add that I have no memory of having to remove the motors, just adding the new clip and greasing the rail, but neither of the two failures involved broken wires, just "tired/aged" white plastic clips, and my clips failed in the mid-way position.

As the clips are 20 years old I didn't want to use secondhand ones and have to do the same job in perhaps five years. The clips are only about £1.50 at a VW dealer.

Regards

[ianM]

Hi Arctic, Vitesse

Just wanted to say thanks again for the advice and pics - they were a total lifesaver! Got the job done, and wouldn't have managed it without those pics. Almost feels like that should be part of a "how to" or something.

Thanks again - just wish I knew why they'd died, and if there was anything I can do to avoid it happening again!

[vitesse]

Think it's just a case of old, brittle plastic clips. With a new clip and greased rails there's no reason to believe you'll need to do the job again (at least not on the same door ).

Pleased it's now fixed, and thanks for getting back - so many don't bother.

[Mike Noc]

You can buy repair kits like this if you need more than just the clips.

Just repaired a Freelander rear window with something similar.