[928ram]

Dan,

Here's the actual diagram from the service manual, with notes:

1) the upper "black" wire is actually black/violet, the red wires in pic are actually brown (brown is ground in all things 928), all others are the color they scanned at.
2) The devices shown: at top - 4-way switch
Center-left - side to side cange over switch
Bottom - both mirrors

{pic didn't post right...see below}