Horn LO

Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .)
Remove the front bumper. (See FRONT BUMPER REMOVAL .) (See FRONT BUMPER INSTALLATION .)
Remove the horn LO. (See HORN REMOVAL/INSTALLATION .)
Apply battery positive voltage to horn LO terminal A, and connect the horn LO retaining bolt to ground as shown in the figure, and then verify that the horn LO sounds.

Fig 1: Checking Horn Low Sounds

Courtesy of MAZDA MOTORS CORP.

If the horn LO does not sound, replace the horn LO. (See HORN REMOVAL/INSTALLATION .)