Headlight Problem

[metal chevy]

Ok so here goes my best attempt to explain this. I have new headlights i just put in but when i pull the switch out to turn the headlights on nothing happens. When i pull it once to turn on the driving lights they work though. Im not sure if its the wiring or the switch itself. I bought the new harness piece that clips to the headlights but im not sure if i should go through the trouble of wiring them in if the wiring is still bad somewhere else. How hard would it be to run new wiring to replace the old and hook it up to the switch in the dash? Cause id rather not buy a new switch if i dont need it, or run new wiring when it was actually the switch all along. Thanks for any help.