Horn Relay

Remove relay. Check continuity between relay terminals "A" and "C". SeeFig 1 . If there is continuity, replace relay. If there is no continuity, apply battery voltage across relay terminals "B" and "D". Check continuity between terminals "A" and "C". If there is continuity, relay is okay. If there is no continuity, replace relay.

Fig 1: Horn Relay Terminal ID

Courtesy of MAZDA MOTORS CORP.