Diagnosis And Testing - Horn

Refer to the appropriate wiring information. The wiring information includes wiring diagrams, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds. For proper wire repair, refer to STANDARD PROCEDURE and connector repair procedures, refer to REMOVAL and INSTALLATION .

1. Disconnect the headlamp and dash wire harness connectors from the two horn terminals. Check for continuity between the horn ground circuit connector and a good ground. There should be continuity. If OK, go to Step 2. If not OK, repair the open ground circuit to ground as required.
2. Check for battery voltage at the horn circuit connector of the headlamp and dash wire harness connector for the horn. There should be zero volts. If OK, go to Step 3. If not OK, repair the shorted horn circuit between the horn and the front Power Distribution Center (PDC) as required.
3. Depress the horn switch. There should now be battery voltage at the horn circuit connector of the headlamp and dash wire harness wire harness. If OK, replace the ineffective horn and mounting bracket unit. If not OK, use a diagnostic scan tool and the appropriate diagnostic information for further diagnosis of the Body Control Module (BCM), the front PDC, the Controller Area Network (CAN) data bus and the horn switch.