Hi there. you may have some parts missing here. On the bottom of the horn rod a small compression spring goes on first. Next the spider (with a square female hole) with two lugs on it which engage in the slots of the switch contacts to turn it, goes over the square end of the rod pushing up against the spring. Next the "U" shaped retainer clip slides into a groove around the bottom of the horn rod holding the other two parts on against spring tension. Then refit your switch taking care to locate the two spider drive lugs into the switch slots. There is a wide and narrow lug so only goes one way. See Macs catalog on page 27 for these items. Regards, Kevin.