I just want to confirm symptoms before I order parts. I came out to my car this morning to do some work. I turn the key, press window-down switch, and the driver's door window is dead. I try other windows, and they are working fine. Try the driver's door again - nothing. I can hear that there's a soft click inside the door when I push on the window switch, which tells me that the switch is probably fine.

There is no grinding noise inside the poor panel - just an audible click when you press the switch in either direction, like the motor is trying to push/pull weakly but cannot.

So does this mean I have to replace the window motor in the driver door, or is there a chance something else might be the culprit around the motor that would block the travel of rods/gears/etc...?

Also, how easy/hard is it to replace the window motor on a W126?

I would take off the door panel first.

You say that there is no grinding which I would expect to hear if it was the regulator. When you hold the window switch down, you don't hear anything turning inside the door panel?


Also, how easy/hard is it to replace the window motor on a W126?

You can see the motor once you take the door panel off. I have only replaced regulators, not motors, but motor looks like it would be simple.

I'll try to open up the panel... Someone said, but I forget - you pull it UP after you undo all the screws and tabs to remove it?

You need to remove quite a few things first:

1) The chrome latch plate
2) The inside door handle
3) All the trim around the seat switch and the door opening handle.
4) The seat switch itself
5) The door lock button
6) A piece of plastic trim that sits above the door panel, against the glass, at the very aft end of the glass. This one is vital.........make sure you remove it.

Once all of the above are removed, the panel lifts straight up. DO NOT pull it toward you. There are five very delicate plastic tabs at the top of the panel that are just begging you to pull the panel outward. It will lift straight up until the clips clear the slots in the door. Then, and only then, can it be pulled forward (toward you and away from the door).

Usually the motors are not the cuplrit. You might need to break into the wiring to see if the motor has 12V in each direction from the switch.

What usually happens is the motor strips the regulator teeth because the regulator is not strong enough to handle the torque when the glass is stalled (all the way up).

Alright. I just removed the plastic door panel, and I was just sitting there scratching my head as to what to do next. The inner metal panel seems to be blocking most of the view...

Ok, so I found the motor - it sits right below everything next to the see-saw construction with the gear(s) on it which mesh with the teeth of the motor's gear. Ok.

When I push on the electrical switch, the one "click" that I hear isn't actually coming from the motor. It's coming from somewhere right below the glass in the upper-middle section of the door cavity. I can't actually hear the motor making any sound at all, and I do not see those teeth moving even a fraction of the millimeter when I push on the window switch. Yet, there's that one click up at the top below the glass... weird.

Now the million-dollar question is, how do I remove the motor? Since the window is in the fully CLOSED position (all the way up), I am afraid that as soon as I unbolt the motor from the metal paneling and the teeth disengage from the see-saw structure (regulator?), the window will come plummeting down....

Even so, I have trouble understanding how to remove that... I can see two threaded studs on the panel with nuts on them, so I guess they attach the window motor to the panel....

Help please????

To remove the motor you have to remove the window regulator assembly.
There are 3 bolts that let you remove everything. Remove the plastic and hold the widow up. You will need to take a rail extension off to gain clearence. Once this is removed then the motor can come off. Do a search under Buy Parts on this site look up window regulator for your car and you will see the parts.

__________________
2009 CLS550 55,000
2004 ML350 144,000
2004 X5 95,000
2002 X5 165,000
1996 320S 155,000 (sold)
1991 190E 192,000 (sold)
1989 300SE 160,00 (sold)
1984 300D 210,000 owned since 85, (sold)
1984 300SD 160,000 (sold)

I have solved many window lift problems by repairing/replacing the switch. The contacts become “carbonized” If you are an accomplished tinkerer, the switch can be removed and taken apart, then use fine emery paper to clean the contacts. Viola, Good as new. I have a small deal going with my favorite "auto recycler" doing this.
Jacob

I doubt it is the switch because i recently took the switch off and checked/cleaned the contacts. However, the window motor was pretty loud and rolled the window sort of unevenly, so I kind of expected it would go out eventually.

Dave - thanks for the helpful hints. I am not clear, though, on what a rail extension is... Is it a part of that see-saw structure? I guess I'll run some tape over the door sill in a couple places to hold the window up as I remove the motor and regulator. It does make sense to remove the motor and regulator as one piece because it's simply impossible to see into the panel otherwise...

Tape won't hold the glass. If it falls while you are working inside the door, you are going to be in a world of hurt.

Get two pieces of 1x2 material and use them. Cut them to the required length and you'll have a safe support.

my windows stick because the felt -that hold the window in the track- has shrunk causing the power window motor to click. but, that is also why i got my car for $400. saved it from the junkyard.

The rail extensions hold the window and window molding in the down position.
The window rides in the rail extension in the down position. Use spray contack cement to replace the plastic (vapor barrier) when you are done.

__________________
2009 CLS550 55,000
2004 ML350 144,000
2004 X5 95,000
2002 X5 165,000
1996 320S 155,000 (sold)
1991 190E 192,000 (sold)
1989 300SE 160,00 (sold)
1984 300D 210,000 owned since 85, (sold)
1984 300SD 160,000 (sold)

Once you have the motor removed, take it apart. It only takes a few minutes. I found a lot of rust/corrosion on the bottom of my motor, and it works fine now, in fact, faster than the other 3.

__________________
'82 300SD - 361K mi - "Blue"

"Good judgement comes from experience. Experience comes from bad judgement."

listen, look, .........and duck.

One question - have you confirmed that it's the motor? I found it easy to disconnect the motor wires and jump them with a power supply to see if the motor worked or not. I have saved myself a lot of work before by doing that. I have a portable battery charger/starter and I simply connect leads up from the 2 motor wires to the charger and get an instant check on the motor.

I have done this work on both an 82 300SD and (this past weekend) on an 87 300SDL. If it's the motor, the 87 motor can be swapped out without removing the regulator. Although it CAN be done on the 82 as well, it's easier on the 87. Either way, PLEASE make sure you prop up the window rail with some wood before doing it. The window needs to be in the up position to replace the motor in place.

Have you ever had the window crash on you? I apparently had a slider ready to break and, once in a parking lot, I shut the door ( maybe a bit harder than I should have ) and the glider broke, the window fell down, and it sounded like a bomb went off inside the door. Cleaning up all the little, bitty pieces of glass was less than fun as well.

- Ted

__________________
1987 300SDL 265,000 mi.
1982 300SD 325,000 mi. (and holding)
1956 Packard Clipper 150,000 mi.

Alternatively, one can check the voltage on the connector that powers the motor when the switch is pressed, right? Well, the motor is definitely getting power. It looks like it's been tinkered with before or something because there's several wire ties over it, as though to keep the motor housing together - weird.

When I find suitable window supports, I will try to remove the assembly. Meanwhile, I went ahead and put a new motor on order because I won't be driving the car on simply window supports, and I don't want to do the job twice...

Not allways
You can show voltage on a meter but not enough voltage to run a motor.
The best way is if you can run a jumper wire from the battery direct to the motor and one to ground. This remove all othe variables. You can show voltage (12volts) through poor connections ie switchs,broken wires,poor fuses, bad grounds ect. On this circuit reversing the wires changes the direction of the motor. Up to Down.

__________________
2009 CLS550 55,000
2004 ML350 144,000
2004 X5 95,000
2002 X5 165,000
1996 320S 155,000 (sold)
1991 190E 192,000 (sold)
1989 300SE 160,00 (sold)
1984 300D 210,000 owned since 85, (sold)
1984 300SD 160,000 (sold)