Power windows 2002 325i

I agree with you. The regulators themselves should not cause this issue, unless of course there is excessive play in the regulator linkages, which could possibly cause the window to tilt and therefore leading to excessive resistance.

Trust me, it's the regulator, which on E46s includes the rails. Their durability is terrible. (We have a 1991 Honda Accord with 180K or so on it...and its original window regulators. My wife's 2002 E46 with 70K or so on the clock is about to have its third new one. Grrrr....)

Make certain you disconnect the battery before removing the door panel to de-energize the airbag. The door panel is retained by the usual kinds of clips and some screws. (Remove the screws first, of course.) Follow the proper procedures with the airbag, which you will have to remove. If any of this sounds foreign, pay to have it done. I forget exactly what tools you need but a set of wrenches, a socket set including a 10mm socket and at least a short extension, a #2 Philips driver and assorted Torqs drivers, and an appropriate tool for the door panel clips will probably get you through. Oh, you will also need a small wire tie, and have to remove the motor that drives the window to remove the regulator.

JRE

Sorry, but this is wrong. It's the regulators.

JRE

What is it on the regulator that would cause so much resistance? Is it not possible to lubricate them?

Actually, now I think about it I was picturing the old type regulators, are these regulators cable driven?

Yes. The problem is a caused by a [insert your favorite adjective here] nylon or plastic retainer progressively breaking off the cable until it fails completely. Lubrication will not help. Don't bother to take off the door panel without the new regulator in hand.

JRE