Going by standard wire colors
Horns-Purple/Purple & Black
Horn Switch-Black/Purple & Black
Trunk Lamp Switch-B/Purple & White
Trunk Lamp-Purple/Purple & White
Ignition Key Warning Buzzer-Purple & Green/Purple & Pink
Ignition Key Warning Door Switch-Purple/Purple & Green
Sequential Seat Belt Control Unit-B,G,NP,(PG),YG,YK,YO,YP,YU.
Your wires appear to be purple & Green/Purple & White or is what I think is white, pink?
Even though my first impression would be a horn or light relay, I have not a clue!
Unplug it and see what doesn't work!