Window switches have always been a perishable commodity with MB. As it turns out the switches are usually just dirty. We disassemble them and clean (contacts) them quite often. The large chrome surrounded switches are particularly expensive and clean up well. I personally have never taken one apart but they do it in the shop every day. Its not quite as straight forward on that switch as the black ones (that are also so cheap that you might as well replace them).
If no one comes up with the trick I'll go learn and get back.
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician
[This message has been edited by stevebfl (edited 03-22-2000).]