I reinstalled my Underdash harness and my headlights no longer illuminate. I have a few unused plugs so I think it may be something in that. Maybe someone can enlighten me as to what these things are:

i think that black one needs to be plugged in. look on the junction box they are next too, youll see open ports where they go...if they need to be plugged in. there are some that just sit there and do nothing.