2000 E320 back left window stay down

Hi! So I opened my back left window and it doesn't want to go back up... it makes a noise (sounds like a crunch and struggle) but it doesn't budge... it's an electrical window, doesn't get used often at all. I want to try fix it myself but I have no idea on what to do.... any advice?

Hi! So I opened my back left window and it doesn't want to go back up... it makes a noise (sounds like a crunch and struggle) but it doesn't budge... it's an electrical window, doesn't get used often at all.

I want to try fix it myself but I have no idea on what to do.... any advice?

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