Rear window troubles
 

On my 1991 350 SDL the drivers side rear window is giving problems. It will let down OK but sometimes when it starts back up it seems as if it doesn't catch or something. Would anyone venture to guess what the problem is and what parts I might need? I've seen some window regulators(if this is what I need) on the Internet for around $56 to $120. I was pondering what the cost might be if I took to a dealership or if I should attempt the job.
Thanks in advance for any advice.
Frank

By "doesn't catch," do you mean it makes a "clunking" noise repeatedly while it doesn't go up, or simply that you press the switch and nothing happens?

If it's the former, you need a new regulator- those prices are reasonable (assuming new/good condition parts) and installation shouldn't take more than an hour, although having a friend helps.

If it's the latter, I would recommend opening and cleaning the switch, and if that fails, looking for a bad electrical connection near the motor.

Hope this helps.

It did make a noise one time like it wasn't catching. Once when I got the window all the way back up it vibrated back down a inch or so while on the road. I've been afraid to test it any more since I managed to get it to stay completely closed.
Thanks,
Frank

the question is when you hit the switch do you hear the window motor running when the window isn't moving? if so, the regulator is in need of attention. sometimes they can be 'fixed' by replacing one of the plastic slides but it usually is not as good as just getting a regulator. if not, remove a switch from another working window and try testing it in the questionalble one. if it now works, clean your old switch as the previous poster suggests.
good luck
gregg

I gave it a try after lunch, it's got to be the regulator, I can hear the motor but the window doesn't move. I took my hands and got it closed til I'm able to repair.
Thanks to all for your help,
Frank

Remove the door panal and take a look. On the W126 they come off in about three minutes once you know where the screws are.

http://catalog.peachparts.com/RenderScriptTemplate.epc?_cmd=epccat_VehicleAAA&cookieID=2G510NISS2G510NUMK&yearid=1991%40%401991&ma keid=MB%40%40MB%40%40X&modelid=350%2DSDL%2D001%40%40350SDL&catid=O%40%40Body+Mechanical+%26+Trim&mod e=PA&subcatid=O3044@@Window+Regulator+Roller&source=www.peachparts.com&clientid=catalog.mercedesshop

Mine just needed this...

Yesterday, my window did go down with the power but wouldn't go back up. After playing with it a couple of times the motor doesn't move it up or down. It's like the glass isn't attached to the mechanism. Does this sound like the same problem you had?
Frank