How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask MB Paul Your Own Question

MB Paul
MB Paul, Mercedes Technician
Category: Mercedes
Satisfied Customers: 4317
Experience:  Mercedes Benz Qualified Diagnostic Technician
15777119
Type Your Mercedes Question Here...
MB Paul is online now

My car was sitting for a period with the windows open, over

Customer Question

My car was sitting for a period with the windows open, over 2 weeks unknown to me. The doors and carpets were very wet. The central locking is working, the electric mirrors and seat memory functions are all working as is the boot opening. all these functions are on the interior door panel. The electric windows switch to all windows including the rear isolator switch is not working.

Last night the 4 switches on the door were inop. All the doors separate switches were also inop apart from the front passenger switch. This morning I tried the passenger front and the window went down and now won't return

Can there be water in the switches and will they dry out and return to normal function. Can you tell me if the windows are fused separately and where the fuses are. I have the fuse diagram but ther is no mention of electric windows.

My car is a Mercedes E Class Elegance E270 CDI 2003 W211 Saloon Auto
Submitted: 3 years ago.
Category: Mercedes
Expert:  MB Paul replied 3 years ago.
Hi,

The window motors are not fused as such - each door has its own Door Control Module (DCM) which gives power to the window motor when the switch is operated. The DCM acts as a kind of electronic fuse - if it detects too much current or a short then it simply switches off the power. Many electrical items work in this way now.

If water has got into the door then it could be a problem with the switch or even the drivers DCM

If the car was in our workshop then we would be testing communication with the drivers DCM and checking the signal from the switch using STAR diagnostic tool.

Even the switch is more complicated than a standard switch - there is only one signal wire between the switch and the DCM, when the switch is operated it sends a data signal to the DCM to say what switch is being operated.

Both the switch and DCM are possibilities if water has entered them, even if the water dries out it can quickly cause corrosion to the electronics inside the components.

Hopefully it is just the switch but to confirm this you really need it checked on a diagnostic tool.

You could also remove the door trim panel & check behind for water ingress to the DCM as well & try to dry out the switch & clean the contacts if required with some electrical cleaner. It would be difficult to say if this would be a lasting repair however & replacing the switch would probably be a more sensible solution.

Let me know if you need anything else.

Best regards, Paul

What Customers are Saying:

 
 
 
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil
< Previous | Next >
  • 9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much. Phil
  • Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible. Charles
  • As a single woman, I really appreciate an excellent and affordable opinion.
    Thank you Geordie, I will not hesitate to contact justanswer in the future!
    Sue
  • Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, Frank...you do indeed know your stuff. Jim
  • I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry. Stephanie P
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C.
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex
 
 
 

Meet The Experts:

 
 
 
  • Matt

    Matt

    Mechanical Engineer

    Satisfied Customers:

    482
    BEng hons Mech engineering, in auto industry 22 years
< Last | Next >
  • http://ww2.justanswer.com/uploads/35/350matt/2012-6-7_182356_matsavatr.64x64.jpg Matt's Avatar

    Matt

    Mechanical Engineer

    Satisfied Customers:

    482
    BEng hons Mech engineering, in auto industry 22 years
  • http://ww2.justanswer.com/uploads/EU/eurotec/2012-6-11_13153_mpjaphoto.64x64.JPG Marty's Avatar

    Marty

    ASE Certified Technician

    Satisfied Customers:

    21371
    Bosch Certified Master Technician with over 35 years experience in the automotive industry.
  • http://ww2.justanswer.com/uploads/MI/mikeamechanic/2013-4-2_175558_photo.64x64.JPG mike_a_mechanic's Avatar

    mike_a_mechanic

    Mercedes Mechanic

    Satisfied Customers:

    116
    17 years experience as a auto mechanic, foreign and domestic.5 years running my own repair business.
  • http://ww2.justanswer.com/uploads/MB/MBpaul/2013-8-21_204936_paul.64x64.jpg MB Paul's Avatar

    MB Paul

    Mercedes Technician

    Satisfied Customers:

    212
    Mercedes Benz Qualified Diagnostic Technician
  • http://ww2.justanswer.com/uploads/IN/indytech/2013-8-8_102717_SantoDomingo146598x6402.64x64.jpg Greg's Avatar

    Greg

    Technician

    Satisfied Customers:

    1080
    Automotive diagnostic tech
  • http://ww2.justanswer.com/uploads/TE/techmachine/0601821347169_717372168_8940977_39623330_o.64x64.jpg Ross's Avatar

    Ross

    Diagnostic and repair technician

    Satisfied Customers:

    453
    Licensed diagnostic and repair technician