The horn relay is intended to handle the heavier current required by the horn(s), rather than routing this current through the horn switch/contact at the end of the steering column. Your problem could still be the relay. Put a test light on the terminal that goes to the horn and press the horn button. If the test light lights, the relay is OK. Then you have a problem between the relay and the horn...bad connections, open wire, faulty horn, no horn ground.
