Mercedes Windows Driving Me Crazy

Has anyone here troubleshooted the power windows in an old 300D Turbo Diesel? I know they are diagonally powered(?) I have replaced all of the fuses already. What should be the steps I take here.

Reply to
Bryan
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You and me, both. My 300D will be going into the shop on Friday to have the regulator mechanism of the driver's window looked at, and either tightened or replaced (guess which one my money...er, VISA card, is on).

This will be the third time that I've had to have the driver's- window regulator replaced, in three different cars. It was necessary with my first W123, with my 126, and now with my 124.

What's up with that? These cars are so well built overall, and yet, there are a few areas where they seem downright underengin- eered. Window regulators are one, and reserve engine cooling capacity is another.

Grumble.

Geoff

Reply to
Geoff Miller

There are three areas to consider:

The switches that one pushes - they accumulate dirt.

The relays that do the power switching - they burn out - in a 116 they're located behind the foot well panel to the LEFT of the parking brake pedal.

Finally, the "regulators" (motor units) inside the doors.

Suggest you diagram what works and what doesn't, realizing that the left rear console switch has a lockout for both rear windows.

One can interchange the relays to find the defective one by elimination.

Reply to
T.G. Lambach

On my 80 300SD, 3 original ones are working fine. The one that failed was the driver door. And that failed because I made the mistake of trying to open it when it was very cold outside and it had gone through the car wash earlier. The replacement I got lasted about 5 years. Few weeks ago I replaced that one again, because it too had failed. The plastic bushing in the regulator arm slide was shot. Unfortunately, that is not replaceable as a seperate part. (Or if it is, I can't find one anywhere).

The replacement ones are not as good as the originals. I guess you could get one from the stealership. The first replacement one I got was from an online parts store. I think I paid around $140 for it. As I said, it lasted about 5 years. This one I got on Ebay for $75. I've since seen them on there for $50. When I put this one in, after getting it all lined up, which ain;t easy, I tried to put the bolts in. One wouldn't start because the threads were not cut right. I didn't think I even had a 6mm tap, till I looked. But I did and then I remembered why. The one I got from the parts store 5 years ago had the exact same problem and that's why I bought the tap! So, you can get the same thing on Ebay or pay 2 times more and get it from a parts store.

I did spend more time fine tuning it this time. I think part of the reason the replacement one failed last time may have been that it wasn't adjusted correctly. This time I made sure it's perfectly aligned. I also made use to thoroughly coat the arm slide with grease. She goes up real nice now, faster and smoother than the originals. Hopefully it will last.

As a side story, when I did this job, I temporarily unfastened the vacuum switch on the drivers door. This is the vacuum switch the key moves to activate the central lock system. I finished the door job and had it all back together and next day went shopping. When I came out, the other doors did not unlock. So, even though all I did was move this thing out of the way a bit, never even unhooked vacuum hoses, you would think something I did must have screwed it up. So, I take the door apart again and start tracking it down. Turns out the vacuum line going to the door from the engine compartment had cracked right at the firewall. Had nothing to do with me taking the door apart, pure coincidence!

As a tip, this is the second vacuum line that has cracked at that exact same point. The other was the engine shut off vacuum line. That line made a sharp bend as it went through the rubber grommet, which I assumed was the cause of the failure. This one went straight through, no tension on it at all. So something else is going on, whether it;s vibration or maybe because there is a steep temp change at that point from the hot engine compartment, etc, I don't know. But if you have a vac problem, that is a good place to look. When I pulled on the bad ones, they just broke off.

Reply to
trader4

The electrons are stuck someplace. Find out where.

First step: pull (pry up actually) the switches and short the wires together thus taking the switch out of the loop. If the windows moves it's the switch. Take it apart, clean it then put it back.

You do have voltage at the switch, right?

Did you clean the contacts of the fusebox with a pen eraser?

Reply to
Richard Sexton

After I've rocked the heck outta the switches to see if they are sticky, I pull the door panel, disconnect the wires to the window motor and use a battery charger to pwr the motor and see if she moves or trys to. If yes, then I start working down the circuit until I find the problem. If not, then it's a dead/weak motor.

Reply to
PT in OR

After I've rocked the heck outta the switches to see if they are sticky, I pull the door panel, disconnect the wires to the window motor and use a battery charger to pwr the motor and see if she moves or trys to. If yes, then I start working down the circuit until I find the problem. If not, then it's a dead/weak motor.

Reply to
PT in OR

and later, I repost the same thing for the back two windows...

Reply to
PT in OR

Hee hee hee

My guess would be the switch..I've swapped the switches from left to right, (on a two door) and located the bad one easily.

Taking them apart are fun, watching as the springs take off, never to be seen again

New ones are around 20 bucks from the dealer, or free (pocket parts) at the local Pick and Pull junk yard

Reply to
Ken

It doesn't really fly out... just hold and release the tension slowly.

Reply to
Tiger

My '87 W124 250D (5 cylinder, 2.5 liters, do I understand correctly that these were called 300D in the US?) had the same problem: rear right window stuck. I noticed it starting to fail intermittently before it finally stopped altogether. The motor seemed to give a faint click when I rocked the switch. Swapping the switches didn't make a difference.

I took it to the (independent) garage this thursday. The mechanic took the motor apart and cleaned the brushes/collectors. The window now works even better than the others. Just cost me the labor (not sure exactly how much, also had some motor mounts replaced, windshield wiper motor fixed and regular maintenance at 140 EUR labor).

Ximinez

Reply to
The Spanish Inquisition

Yes; they're known as the 300D 2.5 here. I have one and love it.

[mechanic cleaned window motor]

Glad it worked out so easily and cheaply for you.

In my car's case it turned out that the gear of the regulator mechanism was missing several teeth, so the regulator had to be replaced. It was a hundred and some dollars.

Oh well, at least it was Friday...

Geoff

Reply to
Geoff Miller

Contrarianally, I would like to observe that I despise electric windows.

A manual window can be easilly adjusted with little thought or effort. A mere swipe of the hand is often enough.

An electric window requires finding the correct little switch and moving it the right way for the correct amount of time. It is annoying but apparently considered such a luxury that manual windows are being phased out.

.
Reply to
greek_philosophizer

Have had both on cars.....but I also have long arms and can roll down the right window without any problem.

Advised my SO to get manual window's on her mini-van, but she now wishes she had power. Mopar van power window's have a nylon "tape" that breaks. (have changed several of 'em)

Changed the regulators in the SL, cause of the teeth being chewed up, another broke due to driving the washboard backroads of Arches NP

Reply to
Ken

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