Horn does not blow

Have you checked the fuse?

Been reading some threads about the clockspring or spiral wire that runs your horn, aig bag wiring and cruise control going bad and needing replaced. Find more info at--- clublexus.com

It's the wiring harness around your steering column. Use caution while inspecting connections. They advise to take negative battery cable off so that you don't get hit in the face by the air bag if it happens to deploy by accident.