Mercedes 320 year 2002

My Mercedes model 2002, series 320SW, model C3. VIN
WDBRH64JX2F210836 has the following issues from the moment I got it,
.
1. Lock/unlock the car, and all lights work. Turn light switch to "on"-position:
then  no lights, fog lights or whatever; no dashboard light either. The switch
indicates with little green lamps, that the fog lights are on (but they are not)
Checked fuses, but the lights are electronically controlled.
2. Buttons on the rear mirror do nothing
3. Adjustment of both right and left outside mirrors does not work

I know the ECU has been replaced by former owner before he sold it (not
by Mercedes, old one was overfloaded with water, did not function any
more, and thrown out) Anyone has a clue where to look for finding the
problem ?.