Help needed, all 4 electric windows not working on 1995 C200 elegance

[oldrover]

I am trying to solve a problem on a relatives 1995 C200 Elegance automatic that he has recently bought.
All 4 electric windows do not work, I have checked the two 30A fuses in the boot both intact, and had a look at the control unit next to the battery.
When each window switch is pressed each corresponding relay clicks in (I removed to cover from the unit) and could see and hear each relay click.
Also when I tested with my voltmeter there was 12V present when each relay clicked in.
Are these control units prone to failure?
Also the electric sunroof worked perfectly and this seems to be controlled by this unit.
Really appreciate any help.
Regards, Oldrover

[Jims202]

Sounds like there may be an issue with the wiring from the relay to the window regulators since you have 12 volts to the relay. You can do two things,replace the relay and see if they work and it that does not solve your issue then check each window regulator to see if they are working,to do that you have to remove the door panel and look for a green and a black wire that runs from the regulator motor and run a ground to the black and a hot wire to the green and see if that works if they still dont work then you have bad motors.

[oldrover]

Sounds like there may be an issue with the wiring from the relay to the window regulators since you have 12 volts to the relay. You can do two things,replace the relay and see if they work and it that does not solve your issue then check each window regulator to see if they are working,to do that you have to remove the door panel and look for a green and a black wire that runs from the regulator motor and run a ground to the black and a hot wire to the green and see if that works if they still dont work then you have bad motors.

Hi,
Thanks for your reply. Have read other posts about the rear window regulators causing problems so will check that out. My thinking was that all four window motors cannot be faulty so what is common to all four - window control module, possibly, but could also be rear regulators.
Thanks for your motor 'hot wiring' info. might give that a go before spending any cash!
Cheers, Oldrover

[strictlyspeakin]

All 4 is an odd one. Post back how you make out at the door panel.

[oldrover]

Thanks for replies,
I have just ordered a control unit for the electric windows so will swap that next to see if that solves the problem. If not I will hot wire the rear windows as mentioned in the posts, will post my results!
Cheers, Oldrover

[Sulaco]

Sunroof is not controlled by this unit.

My trunk was once flooded and underwater. This stopped all my windows from coming down. I was having the same issue as you. You press the switch, you hear the click in the relay, you see the two points connecting in the relay, but nothing happens. I never quite figured mine out, either. I just cleaned the contacts between the 2 points in the relay, then cleaned the relay itself with some electronics cleaner. I cleaned the contacts for all of the 40+ wires going to this relay. My windows worked better from that point on, but were never perfect. I wish I were more help.

[oldrover]

Hi,
Just changed the control unit (one behind the battery in the boot/trunk) made no difference, still all four windows not working, can hear each relay clicking in control unit but nothing.
Have not checked motors in doors yet, but cannot see all four motors being faulty.
What other common thing could cause this? Is there a connector that could be loose, or a bad earth?
Thanks to all replies,
Regards, Oldrover

[strictlyspeakin]

I see 2 different fuses (F1 and F4) and the CANbus connector in common. There is a relay in the engine bay too, but I can't figure out what it's doing. I'll look more tomorrow. Of course the cd with the diagrams is acting up.

[Sulaco]

This one has me completely befuddled. Best of luck!

[oldrover]

Thanks for having a look. I have found two x 30A fuses in the boot/trunk (No.7 and No.10 if I remember correctly) these are just infront of the battery and both OK.
Do you know where I can find the CANbus connector?
The relay in the engine bay could be worth checking also, if you find where it is please let me know!
Cheers, Oldrover

[taz069]

I just went thru all the above listed problems and finally broke down and bought a new window switch unit off ebay. And here to report in that now my driver window now has the up function!!!!!!!!! All these months of worring with fuses and changing out the relay box in the rear by the battery, It was a simple 60$ switch change. My whole sending unit all 4 switches and the part with the front mirror controls was bad. It was a roll of the dice for me but it payed off in spades!! If you need the ebay seller will post it for ya!! hope this helps!! Did i mention my driver window now goes up!! hehe ,,,,had to throw that in i just tickled pink.

[oldrover]

Glad to hear someone has had some success with their electric window problems!
I am still stuck on what to check next, as the window switches when pressed work each corresponding relay of the control unit in the boot/trunk.
When the cover was off the control unit it actually looks very well made. I did struggle abit with getting the connections off, the end connectors have a locking mechanism that you have to pull down, this mechanism moves the connector into place. Don't remove the plastic retaining clip as this keeps all the cables in the connector, I removed mine and its a bit fiddly to get them back in.
Will post again when I find where to check next!
Thanks for everyones posts.
Regards, Oldrover

[strictlyspeakin]

The connector is in the door sill cable run, but honestly I can't imagine that is the cause.

[oldrover]

Hi strictlyspeakin,
I agree with you about the connector but thanks for the location information. You also mentioned that there is a relay in the engine bay that has something to do with the windows, do you know which one?
Regards, Oldrover

[strictlyspeakin]

There are 4 different diagrams depend on the year, but I can't tell which applies because all the notes and links are hosed. Now that I've spent some time piecing it together I think the right diagram is 80452000wb. In this diagram that relay is not mentioned. But to answer your question, the relay I was referring to is the Wiped area limitation control module.
It appears it is for another year. But I still can't understand why it would be involved. Sorry for the earlier confusion.

You changed the a control module in the trunk, I can't find anything else in common that you haven't checked. You have to get inside one of the door panels and see if voltage is making to the motor. Check fuse 8 instead of 10.
Just to make sure we are talking about the same module, in the diagram there looks like there are a lot of connectors on it. Does that match what you saw on the one you changed?


I've got to see about getting a new version cd from MB.