Abstract: A steering wheel hub includes a mounting plate which mounts the base of an air bag module on a pair of spaced posts. In one embodiment a pair of horn actuation switches in the form of spring contacts are mounted on the mounting plate between the posts and the upper edge of the plate. The spring contacts are insulated and bias the plates apart. Depressing the upper portion of the air bag module rocks the module on the posts, which deflects the spring contacts into electrical contact with the mounting plate and blows the horn. In another embodiment, the base plate is mounted on the mounting plate by two spaced posts which mount compression springs biasing the plates apart. Modular horn actuation switches are mounted between the posts and the plate upper edge. Depressing the upper portion of the air bag module rocks the base plate into engagement with the switches to blow the horn.