Known problem!!
Switches , IIRC, are the same.
The wiring for the 924S windows is obtuse - the power is fed through the operating panel on the drivers side. So in mine the driver can move the passenger window down and up, but my passenger can only move the window down...
I'm afraid in the end I gave up and accepted that that was the way it was going to work for me. There are other threads on this and I believe an article in Clark's Garage.
The other thing that helped was to remove the door card and after carefully working things out remove the motor spiral drive. Over the years of use the Grease dries out and the resistance to movement becomes more than the motor will overcome. Eventually the fuse will blow, the motor damage itself, or the switch not pass sufficient current.
My drivers window came to a halt in this way - it took a full afternoon's work, plus scraped knucles and a lot of swearing but the motor was eventually removed, cleaned up and re-greased with a modern grease before re-assembly. The difference was total!!
Horrid job though. - Good luck.
BTW I found there was little difference in cost between PorscheApart and the far-famed Exeter OPC when buying replacment switches - note the plural......
