I have a 90 300d 2.5 turbo. The driver's power window works fine. All the others don't. The three remaining windows make a click in the relay under the rear seat when you push the button in the console or on the door. The front passenger window also seems like it is getting power to the motor because I hear a sound in the door. The safety switch seems fine. I tried changing switches with some other used ones and no change. I have almost 12 volts (11 volts with ignition on) at the rear window switch in console. I took apart the big relay under the back seat and opened it up. It looks fine. As my next step, Should I take apart the door and try the motors with 12 volts? Or just open up the rubber that covers the wires going to the doors and look for broken wires?
Which wire should I check for voltage on coming out of the convenience relay under the rear seat?
On a positive note, I fixed the power seat switch today. It wasn't sliding back, but after a bit of work it is now working. I also recently fixed the oil leak at the tensioner bolt, replaced the vacuum pump with the updated version, and replaced the tensioner pulley. The brakes are working better after cleaning up the sliders and replacing the boots. Now I am just waiting on the right tool to take the exhaust off up by the turbo to bring it in to weld a new flex pipe in.

You should pull the door card and check to ensure the motor is getting full current and that the wiring is in good shape. Additionally if they have been this way for a while, they might be stuck. You could try using a credit card and run it around the inner and outer rubber seal around the glass to break any bond, possibly also using a window glass suction cup to apply some downward pressure on the glass as you work the switch. My passenger rear window sometimes sticks because it is the least used, but freeing it up, has been working ever since. Now I periodically run all the windows just to keep them free. Also graphite powder is great for lubing the window channels.

Good luck

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Stable Mates:
1987 300TD 310K mi (Hans)
2008 Jeep Grand Cherokee OM642 165k mi (Benzrokee)

Thanks for replying! I will take the door apart starting with the passenger door. That one sounds the most like it is actually getting power. It will be nice to lube everything up in there while it is apart.

I've had broken wires in two W124's, both Rt Front windows wouldn't lift.

I fixed my '87 300D by carefully cutting out the broken sections where insulation had crumbled and splicing new wires. This was a tedious job but using high quality US wire from the aerospace industry it has held up fine.
I just haven't the energy to tackle my '95 wagon yet.

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'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!

On my 95 E300D my window problems have primarily been related to the module beneath the rear seat. Those small relays have very small contact points. I've been very careful to clean them due to the small size. I did order about 20 of the small relays, but have been fearful of replacing them due to fear of not soldering them in correctly.

Plus I've been able to source a few spare modules.

I believe there is a larger relay near the master cylinder that I replaced since it provides power to the rear seat module.

In troubleshooting window motors I use a battery charger to provide a higher voltage if the window motor doesn't move with battery voltage.

If that doesn't work I take the motor out and take it to a nearby repair shop to see if it can be repaired. We're lucky to have small shop nearby that is family owned & they have years of experience.

And the fuses should be replaced with copper contact ones to get better voltage transfer and current flow.

not all W124 have that module. It was the convinient module I think.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

The W124 power window wiring has an inline thermal circuit breaker on the doors themselves, it cuts if the motor demands too much power to move. Its the screw attachment point of the window wiring on the door chassis. Check for corrosion there.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)