Just wondering if your problem ever got solved. because i am having the same problems i replaced the gm, the fusible link the only thing that ever got fixed was the window wipers would work properly and not only on high.
Also how would you check the ignition switch what do i need to check it also how much would it cost to get it checked at the dealer. Its driving me crazy that i cant roll down the window because i live in the desert.
I drive a 92 525i i love the car to death but fixing this thing is driving me crazy.