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hey guys!I have this problem for almost a month and it is really annoying.windows won't go down or up with doors close(I hear the click sound but windows won't move).work Fine with the door open!I have Checked the fuses, they seem allright.
Car : w124 260 1986
Assuming your car is an '86 as shown in your profile, this sounds like a problem with the infamous power seat diode. Power flows through this diode to activate the power seat relay when the ignition is on. If the diode blows open, you will experience just what you are reporting. If the diode blows shorted, some car accessories will come on when you open the door (and other strange things).
The seat diode is located in the relay box directly behind the fuses. You will need a phillips screwdriver to remove the cover to get at it. It is the only 2 pin module in the box. Google "Mercedes w124 seat diode" for a picture of one.
If you're handy with a soldering iron, you can replace the diode (use a 1N400X) in your current module for about 50 cents or you can buy a new one for about 20 bucks.
Thanks for responding ,I don't have power seats Can it still be that diode you are talking about?and is that it?
in this last picture i have taken the relay out .it was at the end of the box in right
My bad on a couple of fronts - I read "windows" and thought "seats". I also didn't pick up that your car is non-US and thus may not have power seats. The schematics I have are for US spec cars which may be different that euro spec, so I may have to take a few guesses.
First, if you have no power seats in your car, then, in theory, you should have no seat diode, but clearly you do have a diode in place. I'm guessing that in the absence of power seats, MB uses the same circuit design as they do on the seats. The diode you show in your picture looks like it has been hot (melted plastic behind it), so I would check the diode with a multimeter on the "diode" setting. If it's open/shorted, replace it.
Question 1 - Do the windows behave the same with the diode removed?
Question 2 - When you say that the windows work with the door open, is that open with the key on or just open (key on or off)?
Also, I know you said the fuses looked okay, but remove and inspect fuse 2 - sometimes the fuse looks good, but the connections are corroded.
There is also a power windows relay that can fail, but I would tend to doubt it since the windows work under some conditions.
Lastly, inspect the driver's door switch and make sure it is in good condition.
no it does not have power seat and yes it is EU Spec. Today i tried to pull the diode out and i broke it.i think it has been as you said hot before because it was a little bit crispy! and i think they tried to keep it together using glue
1-windows behave like before without the diode
2-it doesn't make any different with key on or off when you open the door you have power windows working!
i have checked the connections on drivers door switches no change!
If the diode package was that fragile, clearly the diode element was damaged before you removed it and so needed to be replaced. I had one more question - did your windows always work with the door open as well as with the key on or is the door open part new?
Last edited by Floobydust; 01-25-2017 at 10:35 AM.
Reason: typo
If the diode package was that fragile, clearly the diode element was damaged before you removed it and so needed to be replaced. I had one more question - did your windows always work with the door open as well as with the key on or is the door open part new?
I don't remember correctly but i guess yeah it wroked this way before
As I mentioned before, you car does not seem to be consistent with the schematics that I have (e.g., if you have no power seats, you should not have a seat diode), so I'm speculating more than usual. I would replace the diode unit in your car and see if that solves the problem. Please post what happens.
Hi,Thank you Floobydust and you Google too!
I went and bought the Diode IN4003 And Replaced it with the burnt one.
Windows Are Working great like before BUTTT!!! yesterday Right Window in the rear Worked fine but today after changing the diode it's not working!It Might be the switch on the door, gonna test it tomorrow.
A problem with a single window on the early cars when the others are working is usually a switch or a motor issue, although rarely the wiring can fail where it flexes at the door hinge. A problem on just the left or the right side points to a fuse issue (fuses G & H).
01-21-2017, 04:25 AM
help!no power windows when doors close
It Might be the switch on the door, gonna test it tomorrow.
