Drivers Side Window - PeachParts Mercedes-Benz Forum

tobybul · #1 08-09-2006, 05:03 PM

85 300D My drivers side window quit on me today in the open position. I am guessing its the switch. B4 I start fiddling with it can someone tell me how to pop off the switch? Also, could this be the problem? It did show some sign of acting up intermittently b4. Now it went out. Could be just the switch. The switch's spring load feels fine.

dougand3 · #2 08-09-2006, 06:02 PM

My 126 has center console "double" switches...I assume the 123 is similar. 2 spring clips hold the switch in at the ends. Thin flathead screwdriver will lift switch up slightly and then depress clip...switch should move straight up. Now, the clips may be brittle and break...mine did. Plastic side pins hold the switches together. Open switch over a white towel...there are small "lazy V" plates and tiny metal balls inside. Mine were full of coca cola or something. I used brake parts cleaner and sandpaper to clean contacts.

Probably not your problem, tho....the gearbox atop the lift motor is probably becoming faulty/seizing or may be the motor brushes are worn out/too dirty. I've never seen shops selling just lift motors or just gearboxes....always a combo unit.

For now...try pulling door panel and tapping motor moderately while depressing up switch...you may get window up.

Soon, tho...I suspect you'll need to pull regulator and replace gearbox/lift motor unit. If you do it yourself...CAUTION - spring tension...when the regulator is out on a workbench...removing the 3 gearbox bolts unleashes this tension...the regulator arm and spring plate need a hole drilled thru them and then bolted together or it gets ugly.

alan911 · #3 08-09-2006, 06:32 PM

If it's a switch, just substitute the left rear passenger switch for the drivers side switch. If it works, it's the switch. If not, then go through the hell of removing the door panel ad screw with the motor.

The drivers side switch and motor gets the most use up....down.....slaming the door.... so.......it's ususally the first to go out.

300Dguy · #4 08-09-2006, 09:40 PM

Are you having any problem with the passenger side rear? If so, it may be one of your 16 amp fuses (A or B) that serves these two window motors. Just had this problem with my Passenger front and Drivers rear. Fuse looked fine, however corrosion on the contacts was the problem. Cleaned up the ends of the fuse and the fuse box contacts with sandpaper and the problem was gone.

tobybul · #5 08-10-2006, 12:30 AM

I pryed and pulled the the switch up, no problem. Tapped it lightly, operated it and it worked. I suspect theres some dirt inside affecting the contacts and will probably need some cleaning.

I'll have to open it some other time.

I still don't understand why MB placed theses switches in the center console like this even on the newer cars. Its so prone to spills and whatever else. Plus its not the easiest to operate unlike if it was put on the drivers door armrest like all the other cars out there.

Thanks for the suggestions folks.