As the title says. The headlights turn on, but they don't light up signs in the distance, and show a very weak projection, similar to marker lights/low beam. This makes signs impossible to read in the dark, as they only become visible a few meters from the train. AI trains seem to project lights as expected. The ones I own that I can't drive in the dark: 766.2 DBpbzfa DB from Lübeck DLC (The Kassel one works) BR 112.1 DB BR423 DBKS
This has always been the case since tsw released. Headlights were never made bright for various reasons. The tsw3 routes got the lighting overhaul so their headlights are brighter than other trains. Some tsw2 routes have good headlights such as for dra and dcz