I need help asap

ive been having this problem since i bought my car, the issue is that the lights dont work properly for some reason, things like the brake lights dont work unless i turn all of the cars lights on, the front lights are low as well, the turn signals do work but the ones on the sides are reversed for some f###ing reason. When i bought the car the light-switch module was fried as well as the harness, they were burnt so i replaced them with a different harness and a different light-switch module. After doing the soldering and stuff i realized that there was an extra wire on the harness, it was purple and there wasn’t any purple cables on the old harness as well but im not sure if thats the issue. Ive replaced all the switches as well so it cant be that. I dont know what to do or whats the issue so i would appreciate of someone could help me fix this bs.