electric front windows

[johnsurveyor]

Can anyone help me sort out my front windows which stopped working at the same time, I have seen postings which discuss motor problems but i presume each has its own motor, and I cant believe they failed at the same time. I did have a small bump at the back of the car but all the fuses seem OK

 

[pascal]

John, Welcome to the forums,

It would help if you told us what car you are driving.

Having said that, it is very unlikely that it is anything got to do with the motors.
How many times have I heard people say 'My fuses seem alright', only to discover after taking their car to pieces, it was a faulty fuse all along. Fuses on MBs deteriate with age, and can be all replaced for the price of a pint.

Pascal

 

[tom7035]

As pascal says, not motors, and it's the fuse contact points which deteriorate over time and cause problems. For a start, spray the fuse block contacts with electrical contact cleaner and just move the fuses about in their slots a little and see what happens, then take it from there.

 

[johnsurveyor]

window problems

Sorry for not stating car type
C class saloon, 280S, P reg
both front windows and mirror adjusters not working, the handbook says they use the same fuses both under bonnet and in boot, have renewed fuses and sprayed them with cleaner. The rear windows are ok

They seemed to stop working when i broke the right hand rear light cluster and renewed it, but this may be coincidence.

Any ideas?

 

[nick mercedes]

Sorry for not stating car type
C class saloon, 280S, P reg
both front windows and mirror adjusters not working, the handbook says they use the same fuses both under bonnet and in boot, have renewed fuses and sprayed them with cleaner. The rear windows are ok

The mirrors and the windows share a switch, or it could be the comfort relay in the boot (on the right hand side).

 

[blassberg]

I had a switch repaired under warranty (ML270)

It went with one of the windows down ahead of a must-do 250 mile journey. MB were great. Intercepted me en-route. Overrode the switch. Isolated it and booked me in for a repair.

 

[coully]

if you disconnect/reconnect the battery, do the windows and mirrors start working again for a while? I have the same prob with my 1998 C250 and this resets the window control modules. These stupid cars have a CAN network and i think each window has its own control module. Findin out which is the dodgy module is apparently not easy!!

 

[coully]

Well, what do you know? The only window that has been working through this problem has now been disconnected (I stupidly removed the door panel and disconnected the plug when some smart arse commented that I could have just taken the fuse out!) and the problem seems to have gone.
So....looks like the control unit in the rear offside door which is an integral part of the motor/regulator is faulty. I am ordering a replacement from Dronsfield breakers (£45) and will let you know if I have further probs.
Bottom line is that this CAN sytem on Mercs is so complex that if it goes wrong no-one seems to know how to determine the failing unit. Back to motorcycles for me and, no, it wont be a BMW.

 

[joe bloggs]

P reg car does not have can system, also the windows and mirror switches are seperate on your car.

Comfort control relay (white relay below plastic floor, forward of spare wheel) could be at fault, if you know what you are doing you could bridge out the main switch terminals to eliminate this, or try giving it a tap. Other trouble area is the main window control unit tucked between the battery and the chassis...did you leave any earth wires off in this area when replacing the rear lamp?