By "pull all the lighting fuses" I mean to remove the fuses from the fusebox and leave them out. Then try your test again with starting the car, turning on the light switch and so on. I have not got the wiring diagrams for the .2 NA cars, so assuming the Turbo is the same as the .2 NA car then all the top row of fuses (the "A row) is dedicated to the lighting. Pull them all out.

This will help isolate the problem to a specific part of the circuits.

 

Did you ever get to the bottom of this, @pulpo ?

 

I'm re-reading this thread and a bit puzzled by my post #25 because the issue did stop after I replaced the microswitches.

I did replace the ignition switch, headlight switch, brake pedal switch, and clutch pedal switch.

the ignition switch, brake pedal switch, and clutch pedal switch are all like $20 each so start with those and if that doesn't fix it try the headlight switch too.

It did stop after I replaced all 4.