So, until today my driver's side front power window worked beautifully - not sluggish or slow in the least. This morning it worked, this evening - nothing. I can hit the switch and I don't hear even a sound.

The passenger front window works, and the driver's rear window also works. The passenger side rear window doesn't - and hasn't in a long time. I haven't had time to get in there to solve it, but I am wondering in the mean time what could have killed my driver's front window so quickly?

It's a real annoyance, and I just know I'd rather figure out what's going on... I just don't know where to start. Any thoughts? Right now I'm thinking either a fuse or a switch is to blame.

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1984 300D Turbo, 326000 Km, Thistle Green Metallic

Ok - I was just down checking out my fuses - all are good. That is, the FL/RR and FR/RL fuses are both in fine shape.

I tried swapping out the fuses, but the problem remains.

A little more troubleshooting, and I think what is happening is that the switch is working fine to actuate the window up.... but not down. When I press up on the FL window switch (with the car off) two things happen:

1) My interior maplight dims just a bit
2) I can hear a very faint "click" from the regulator, like it is trying to raise the window (of course, the window is already in the fully raised position)

So, I wonder: is the switch's "down" contact busted? Or, is there a separate set of wires to actuate lowering the window? When I press the switch to lower the window, I hear nothing (and my maplight doesn't dim at all).

Considering that I was able to lower the window this morning with no trouble, I wonder what is most likely... ? And, how best to go about fixing it?

Weirdly, the RR window exhibits exactly the same symptoms. I've just lived with it for now, but hey, if it is easy to fix I might as well do them both. I might make a project of it this weekend.

Thanks for any help! I think at this point I could also benefit from any tips on:

1) Taking apart the switch area of the centre console (like, near the gearshift)

2) Pulling off the dor panels cleanly, to get inside the door.

I have the FSM though, so I think I can get all this done on my own without much trouble. Help is always welcomed though

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1984 300D Turbo, 326000 Km, Thistle Green Metallic

The front window has only two wires going to the motor. They both get used for "up" and "down." Same wires, reversed polarity. So the fact that the window will go up would suggest the problem is not the motor or the wiring between the switch and the motor. That leaves the switch as the prime suspect. You can carefully pry it out of the console with a small screwdriver, remove the rockers and clean the contacts. Don't loose the small parts that will fall out.

The rear window is a bit different. Because of the switch in the door, there are more wires involved in the door itself. It is likely that the "down" wire between the console switch and door switch has broken. Especially if neither the console nor door switch will operate that window.

Cool! Thanks so much for the helpful hints. Thinking about it now, of course it makes sense that the switch should be the prime suspect. Also I can certainly say that the switch I have is the original (now 24 year old) switch. I guess it has to die sometime.

What's the easiest way to get the switch physically out? That is to say - should I be pulling up the wood console that the switch is mounted to? Or can I just use a tiny jeweler's screwdriver the pop the switch out all by itself? That seems like the easiest route.

I'll see what I can dig up on actually repairing the switch. That doesn't scare me too much, since I've managed to repair more than my share of tiny microswitches in my time. I'll probably do it this weekend and will be photographing the process and taking notes too.

Any (other) tips I should be aware of in advance?

Also - yes, it is true that neither switch (console or door) will actuate the rear window down at all.

Finally - the window safety button in the driver's window switch. What is the correct functioning of this button? The behaviour I have observed seems to suggest that this switch will either disable all windows aside from the driver's window, or not. Windows that are down are allowed to go up when it is engaged, but are not allowed to go down. This seems right to me, but I am not totally sure.

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1984 300D Turbo, 326000 Km, Thistle Green Metallic

That will work. No need to remove the console.

Normally, the safety switch only prevents any operation of the rear windows from the door switches. The console switches should still work in both directions. (The safety switch breaks the ground connection for the rear door switches.)

When you remove the console switch, disassemble it by prying the rocker off its hinges. Do it over a container or rag so you don't loose the small parts that will fall out.

The rear window is most likely not working because of a broken wire in the little rubber boot that goes from the pillar to the door. You can pry the rubber boot out and pull out enough slack to fix the wires. That is what I did. The rear window wire kept blowing the fuse so I had to fix it.

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1987 300TD 309, xxx 2.8.2014 10,000 mile OCI


Be careful of the toes you step on today, as they may be connected to the ass you have to kiss tomorrow. anonymous

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter won’t mind.” Dr. Seuss

Interesting regarding the safety switch operation. My safety switch seems to disable all the windows except driver. I am not sure why that is.

As far as the passenger rear window - mine isn't blowing the fuse at all, but the wire being broken does seem likely.

It's good to hear I can just gently pry the switch itself out of the console. That seems like it'll be pretty easy. I'll give this a shot tomorrow maybe and document how well it goes. I am not sure if I saw a good how-to guide for taking the switch apart, but I am sure it is relatively self explanatory (especially if I take plenty of reference photos).

I wonder if just flooding it with a good electrical cleaner might work too?

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1984 300D Turbo, 326000 Km, Thistle Green Metallic

My info is for the '82 models. Maybe the '84 is different.

Success! I just fixed my driver's window - it was indeed a dead switch. I have to go back in tomorrow, as it seems I may have connected up the safety switch backwards... ? It no longer disables the rear windows as it used to. Also, I appear to have killed the passenger window in the meanwhile... oops! It worked fine before I took the switch out, but on putting the switch back in... nothing.

At least that can wait - since the driver's window is the one that gets the most use.

As a bonus, I also managed to take apart, clean and reassemble my 4way flasher switch, which fixed it too!

I know they were just tiny repairs... but it feels good anyway!

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1984 300D Turbo, 326000 Km, Thistle Green Metallic

Working on this rocker switches in the past I have found a good way to clean them is with contact cleaner. I also "spin" a pencil eraser over the copper contacts to polish them up. It's easy case the eraser comes with a convenient handle... the pencil !!!

Funny - I actually used the very same technique! The rockers themselves I had good luck cleaning with one of my wife's emory boards.

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1984 300D Turbo, 326000 Km, Thistle Green Metallic