Classic/Antique Car Repair: chevy horn, good luck jack, wire resistance

Question
i have a 71 nova and connot get the horn to blow have replaced relay and horn button assembly checked the ground and wire resistance on the wire to the horn and it is good

Answer
Assuming that the horn works.  Just connect a hot wire to it to make sure.  Then confirm that the horn wire from the horn has power, or gets to ground.  I'm not sure how they made it work.  either way, you should be able to check the wiring while someone pusshes on the horn switch.  If that is good, then you have an open wire.  Thats about all I can suggest.  Try these things and get back to me.
Good luck
jack