My left rear window is stuck in the halfway down postion on my '85 300TD wagon. Actually, it will go down, but will not go up. I've replaced window motors before on these but before I take the door apart, how do I diagnose the motor or should I just assume it is the motor? I ask because when these have failed in the past, they've always stopped working in either direction.

Oh, also I have tested and ruled out both switches.

I should just keep a stockpile of window and antenna motors -harv

Probably not the motor if its moving.
I'm guessing the regulator is missing a few teeth or is otherwise bent.

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^^I'll agree. But you'll have to open it up to fix it.

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83 SD

84 CD

You might want to remove the window and make sure that the metal channel in which the glass is mounted at the bottom is not catching on the arms of the hoisting "X" mechanism. That happened in mine--twice.

Pull the window out and measure the channel width. Should be about the same all along its length, with nothing sticking out (mine rusted out and splayed...I repaired with epoxy and carbon fiber and then had to trim that down to avoid the catching problem.)

Good luck!

John Bonds, '82 240D, 4sp daily driver
Charleston SC

What I did to test my motors was to take the Connector apart and carefull pull out the 2 Window Motor wires with their female bullet connectors attached.

Hook 1 motor wire (+) and touch the other Motor Wire touch to (-) and see if it works. Swapping the wires around to the opposite poles changes the direction of the motor.
If the Motors Work this way you know they are most likely OK.
This was my rear window problems:
Extreme Rear Window Regulator Repair,123

I also ended up dealing with some swith problems also. Note the burned contacts in the switch;I pointed to the worst one.

Attached Thumbnails

 

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84 300D, 82 Volvo 244Gl Diesel

All good advice...not sure I quite understood the cross connecting of teh motor wires to test the motor, but I can probably figure it out when I open it up.

I'm still suspecting the motor tho. When the regulator plate bend on my front drivers side, I heard the sound of the metal scraping....this window goes down without any sound, but will just not move in the up direction....plus I cannot hear the motor humming when I try to get it to go up. Will open it up tonight.....

Thanks -Harv

OK, I finally found time to open this up. Yes, the plate is bend, but just slightly and it looks like that was not the problem (although I am replacing it). With the motor out, it rotates only in one direction....when I switched the wires, it still rotates only in one direction, but as expected the other direction.

So, what did I learn....is the motor OK and the problem is in the wiring or switch? I think I need help answering this question. Thanks -Harv

Swap switches, that may help determine the culprit.

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83 SD

84 CD