Check the
Fuses before electrical diagnosis. First, unplug the electrical connector of the horn. To test the horn, connect battery voltage to the horn terminal with a jumper wire. If the horn doesn't sound, replace it. In the event that the horn sounds, check voltage at the terminal with the horn button pressed. Inspect a poor ground at the horn if there is voltage at the terminal. A volt check of the horn or horn
Relay is done. If the relay is okay, check for voltage to the relay power and control circuits. If either circuit is not receiving voltage, check the wire between the relay and the fuse panel. If both relay circuits see voltage, push the horn button and check for continuity to ground on the circuit from the relay to the horn button. If the circuit does not have continuity, check for an open circuit-if not, check or replace the horn button. In case of continuity to ground via the horn button, the relay-to-horn circuit has a fault-open or short-or the horn is faulty. For models from 1999 and the horn(s) remove the air filter housing to gain access. To remove the horn(s), disconnect the electrical connector(s) and remove the bracket bolt(s). To install, just reverse the removal.