Window Problems: Regulator or Switch Assembly?
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From: NW Chicago suburbs
'09 CLK550 & 2012 E350
Window Problems: Regulator or Switch Assembly?
Driver side front window went down fine with express down but wouldn't come back up. All the other windows continued to work though. Before I go buying expensive parts that aren't necessary, how do you diagnose which part is actually at fault? Also, using the key fob to get the window closed didn't work. This is a '98 E430.
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From: West Virginia
2001 E320 RWD - Brilliant Silver/Ash: 100,000+
The odds are that your window motor regulator is bad. From what I have read, it is rarely the motor itself. It's also apparently an easy do-it-yourself job if you are comfortable with taking the door apart.
If either of the switches are bad, you should still be able to close the window using that function with the key.
If either of the switches are bad, you should still be able to close the window using that function with the key.
Last edited by Musikmann; Mar 8, 2007 at 10:19 AM. Reason: adding to message
Thread Starter
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Joined: Apr 2002
Posts: 128
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From: NW Chicago suburbs
'09 CLK550 & 2012 E350
The odds are that your window motor regulator is bad. From what I have read, it is rarely the motor itself. It's also apparently an easy do-it-yourself job if you are comfortable with taking the door apart.
If either of the switches are bad, you should still be able to close the window using that function with the key.
If either of the switches are bad, you should still be able to close the window using that function with the key.
The rear regulators have been far more problematic than the fronts. Was there any noise when it went down? Does it sound like the motor is trying to move the window? The switches are part of an assembly that is $360 or so. I would pull the door panel and look around.
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From: NW Chicago suburbs
'09 CLK550 & 2012 E350
The window went down without any sign of trouble but wouldn't go back up. I tried the other windows just to be sure and they were fine. No motor noise comes from the driver door. Is there a separate fuse for each window? I should check the cheapest option before digging into the door.
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2001 E320 RWD - Brilliant Silver/Ash: 100,000+
Sorry, I have no idea about the fuse issue, but as you stated, try the cheapest (or most likely) option first. I still think it's a regulator but as Vince pointed out, I think this is the first time I've heard of a front door regulator going bad, the rears are a much more common complaint in this regard.
Last edited by Musikmann; Mar 8, 2007 at 07:09 PM. Reason: adding to message
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Joined: Apr 2002
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From: NW Chicago suburbs
'09 CLK550 & 2012 E350
I wasn't that lucky. The fuse (40 amps!) was intact. Looks like I'll have to order the part and dismantle the door liner. It's strange that I didn't hear anything. No motor whine.
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I would not order any parts before I took off the door panel and looked. See if the motor is getting the command to raise the window. I believe the window commands from the switches go to a control module and then to the individual window motors. Replacing the regulator can't fix that module if it is the problem.
I would either buy the DVD from MBUSA (P/N P-2700-210-05 for $149.95) and troubleshoot using it or find a good shop that can diagnose the problem. If they determine the problem is something you can fix on your own, then you can buy the parts and do the work. The regulator is an entirely different design than the rear and not very likely to fail (not unknown - just unlikely).
I would either buy the DVD from MBUSA (P/N P-2700-210-05 for $149.95) and troubleshoot using it or find a good shop that can diagnose the problem. If they determine the problem is something you can fix on your own, then you can buy the parts and do the work. The regulator is an entirely different design than the rear and not very likely to fail (not unknown - just unlikely).
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Joined: Apr 2002
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From: NW Chicago suburbs
'09 CLK550 & 2012 E350
Well I was able to borrow a switch assembly from another car to help narrow down the problem. It failed to raise the window so it's either the motor or the regulator. If it was the regulator, I would've thought there would at least be motor noise.
I still think you are making some assumptions. I did some digging. The switch module (N72) sends commands to the individual Door Control Modules (N69/1 through N69/4 - N69/1 is for the driver's door). The command to the motor comes from the Door Control Module. Therefore, if the motor is not working it could very well be N69/1. That is why I recommend finding someone who understands the CAN on this car. It could save $ and frustration.
Interesting thread from another forum that sheds light on a similar problem:
http://www.mercedesshop.com/shopforu...d.php?t=119119
http://www.mercedesshop.com/shopforu...d.php?t=119119





