- Driver's window switch-panel doesn't operate or illuminate buttons.
- Remote door-lock doesn't operate, but all doors operate when key is turned.
- Driver's door courtesy light does not illuminate.
- Mirror control and other door switches do not operate or illuminate.
- Speaker still works.
Cause:
FUSE 10 - 30A - [Driver's Seat Adjustment] It's the first green fuse from the left in the glove compartment fuse-box.
The fuse is labelled Driver's Seat Adjustment, but is really just power from Terminal 30, which also supplies the Driver's Door Module. This module is located inside the driver's door and metes out power to the different door components so that all operations are communicated back to the CAS [Comfort Access System]. This means that when the fuse to the door module blows, power is lost to the window, mirror, etc. switch panel, the remote door lock, basically everything except the speaker. This causes a lot of confusion as to the root of the problem, as it would be very hard to guess that the fuse for the driver's seat adjustment motors would also power a hidden module in the door that controls everything. Oh well, that's modern cars.
There is a lot of conflicting information on forums about this. It appears that most people have the symptoms described above and not one reply mentions this fuse! Owner's have even shelled out for new door modules which have had no effect and perhaps their lack of further contribution to the thread suggest the same sheepish frustration I felt when I found the fuse. Quite a few people have foxed indy auto-electricians with this problem, who have probably been testing wires, as I did, while not knowing about the fuse.
I eventually discovered the fuse by tracing the wiring diagrams on bmw-planet.com. This is a brilliant place to access the TIS wiring-diagrams and navigate them easily. I have condensed the layout of the door module wiring in the pic below.
