The window controls on a W210 run off the body CAN bus. When you press the switch in the center console (known as the lower control panel in the service manual), you are creating a CAN bus message to tell the door control module to operate the window motor.

I would see if the motor is getting 12 V dc across its terminals when you push the switch. Remember this will be using an H bridge circuit with relays (or maybe MOSFETS), so it can flip the polarity to run the window up or down. So you’ll need to measure across the motor terminals and not to ground.

If you’re not getting voltage out try disconnecting the motor controller from the motor and jumping 12 V and ground to the motor leads. If the motor runs the controller is shot. Fortunately these are not VIN specific and require no programming. So any W210 in the yard should have the same DCM part number in its drivers left front door. They are hard coded to their location, so you can’t use a right front, it has to be a left front.

Or of course you can try cracking open the case and see where the magic white smoke came out...

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech