So I've got an interesting issue. 1998 E320 44,000 miles. My drivers side front window has stopped communicating with the window button in the console. The window goes up and down fine with the key in the door to activate it, and also with the key in the trunk to activate it. It will work with the console button but very infrequently. I got a known working window control unit off ebay, and all the other windows work fine. But the front window does not activate with either the old or newer control unit.

Thoughts?

 

I would check the connection to the switch in the center console. If there is an issue with the switch it would explain your issue.