Your first picture..
Lilac is the feed of 12v. it splits, feeds the switch and the end going off the picture is the +12v for your clock.
Lilac Green goes live when you operate the switch and turns on the interior light (not the dash board lights). You can test this with the multimeter. Take off the lilac green cable and test the switch terminal with the switch on and off.
The Map Light next to it. That looks to be wired correctly. The black is the earth, and when the switch is operated it connects the map light circuit to earth (masse gesteuert).
The doors not operating the light - they may have been unplugged at the door contact switches. This is also a lilac white wire on both sides. The lilac white wire from the switch goes to a connector - should be a 4 way bullet connector.

P = Lilac, PG = Lilac Green
Steve is correct. The red brown is connected to the panel light resistor used for dimming the dashboard lights. There should be a red white wire attached to the other side of it.

R = Red, RW = Red White, RN = Red Brown, RU = Red Blue
The first and next 4 RW bulbs are your centre instruments, the next 4 are the Speedo and Tacho, the last 3 on the RU (Red Blue) are the lower dash lights that illuminate the strip at the bottom of the panel.The R on the right, is your power feed from fuse 5 which should have 12v (but only when the park lamp switch is on).




