mis3

When I open my driver door, the front Window would go down a bit but the rear does not move down anymore.

Once I am inside the car, if I power up and down the front window, the rear window would move up and down a bit. So, the motor seems to be working.

What can be wrong?

Rudeney

I'd try resetting the door controllers by pulling the fuses, the re-sync the windows.

mis3

I know there are multiple fuse boxes in this car. Where is this one located? I did the right-sync by rolling up the rear window and held for 10-15 seconds.

I did hear a "clunk" in that area when I powered up my window 2 days ago. Afterward, I heard noises (not the motor noise) when I powered up and down the window. This noise is gone now but the window would not move when I open the door. I do hear the motor but it just would not move.

The noise tells me that the motor is still working. Is it possible that it went out of track or something?

Rudeney

That sounds like the rear window regulator has failed. It's not an uncommon problem. If you want to try fuses, it's #32 for the left, #33 for the right (this s in the cabin, on the side of the dash, behind the steering wheel).

mis3

What does this regulator do? I can still roll the rear window up and down manually by the switch. Only the automatic part does not work.

I cannot find this in parts.com. Do you happen to have the part number?

Rudeney

Oh, so if it works fine by operating the switch, then it might be a synchronization problem. Try pulling the fuse and then do a re-sync.

mis3

I was probably not clear of the symptom. When I open the door, the front window and the rear window would normally go down a bit automatically. When I close the door, the reverse would happen automatically as well. Now, this automation is no longer working.

I did not know there is a fuse box under the dash. Is it located near the OBD connector? Is it a physical box that I can pull out?

Glyn M Ruck

mis3

Thanks for the clarifications, Rudeney and Glyn.

Looks like I have to pull the side panel out. Not sure if this panel was ever removed. In what location should I pull, I am concerned to break the clips...

Rudeney

There will be a small "slot" on the rear edge of the cover, Just pry gently there. It swings out toward the door.

mis3

OK. I will try tomorrow.

I checked earlier today and it seems better.
1. When I opened my door, the rear window would go down a lot but not go backward at all.
2. When I closed the door, the rear window would move up a bit but not go frontward. This makes sense because it did not move backward when I opened the door.
3. After the door was opened, if I pushed the rear window backward, it would move up and frontward when I closed the door.

Sorry. Hard to explain bit hope it makes sense.

Rudeney

This still sounds like a mechanical (i.e. window regulator) problem. Are you sure it functions properly when operating the switch?

mis3

Yes.

The only thing not working is the rear window would not move backward a bit when I open the car door. If it does (like after I push it back), it would move frontward when I close the door.

Rudeney

The fact that it closes after manually pushing it back makes me think the controller is working properly. You should still pull the fuse and re-sync it. If that doesn't help, I think this is mechanical. Maybe the regulator has a bad bushing that binds when it tries to move the few centimeters when opening, but with the switch and fully operating it, it "snaps" past that binding point.

mis3

I just pulled the fuse and no improvement.

To make sure it's the right fuse, I tried to roll up the window with the door switch and it did not move at all. Put it back, then rolled up the window and held the switch for 15 seconds.

As it stands now, the window would move down but not backward. Can I just leave it because there is little impact? I have no wind noise so far.

Also, for future reference, other fuses are harder to reach, can I take out the whole panel?

Rudeney

I don't see any harm it leaving it as is, but if it is a bad regulator, it will eventually fail. Yes, you can remove the rear SAM (disconnect the negative terminal on the vehicle battery before doing so). But you may not need to do that - just get a plastic fuse puller.

mis3

I would rather fix it later when the regulator fails. Do you happen to have the part no?

I did not want to remove the whole SAM. I was asking if I can remove the side vinyl panel to access the other fuses?

Rudeney

The left side rear window regulator is A2096700103. I am assuming you are left-hand drive? You should consider updating your forum profile with your car model, year, and country.

As for removing the carpeted paneling in the trunk, yes, it's easy to do. It's just held in place with plastic trim clips.

mis3

Thanks for the part number. However, I could not find the parts in both parts.com and oediscountparts. Yes, I am in Canada and my w209 is a left-hand drive.

The trunk? The regulator is assessible by the trunk? I would think it would be via the rear seat side panel.

Rudeney

When searching on parts.com, drop the leading "A":

http://www.parts.com/parts/index.cfm...earch&siteid=2

And the trunk paneling comment was regards to your questions about easier access to the SAM. To get to the regulator, you have to remove the side panel trim in the back seat. I know I've posted the WIS docs - search my posts for "regulator" and you should find them. Note that the coupe and cabriolet are slightly different in removing the rear seat paneling.

mis3

Thanks Rudeney for the part number.

It's $390US for the OE parts in parts.com. I called my local MB and they told me this's $770CAN. WOW..

I am going to my indie for a brake fluid change soon (last change was 3 years ago) and I will ask him to take a look.

My regaulator is "mostly" working, I will wait until it gets worse before I change the parts.

KyHusker

Same thing happened to me last fall. Then the regulator failed with the window fully rolled down. Don't wait too long to replace it.

mis3

Same symptoms?
When I open the door, the rear window would move down but not move backward.
When I close the door, the rear window would move up a bit.

KyHusker

Yes. The function where the windows would roll down just a bit when I opened the door stopped rolling back up. Good luck.

mis3

What did you do at that time? Was the door switch able to rmove the window frontwrad to close the gap? Otherwise, there would be unbearbale wind noise.

What strange is if I push the rear window when the door is opened, the mechanism (move up and move foreward) works perfectly. So, the main problem is it would not move backward when I open the door.

Sorry, this is kinda confusing. As per my other post, this regulator costs $770CAN ($870 with tax) and since there is no wind noise, I can live with it.