"U" Series
- If vehicle is equipped with Content Theft Deterrent (CTD), go to next step. If vehicle is not equipped with CTD, go to step 3.
- If horns diagnostic system check was performed, go to next step. If horns diagnostic system check was not performed, perform HORNS DIAGNOSTIC SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM.
- Depress horn switch. If horns have a harsh tone or buzzing, go to next step. If horns do not have a harsh tone or buzzing, inspect for intermittents.
- Check horn mounting hardware for adequate torque. See TORQUE SPECIFICATIONS . Inspect horns for debris in joint where horns attach to vehicle. If problem was found and repaired, go to step 7. If problem was not found and repaired, go to next step.
- Connect a 15-amp fused jumper wire between positive battery terminal and control terminal of horn (Dark Green wire). Connect another jumper wire between negative battery terminal and ground terminal of horn (Black wire). If horns have a harsh tone or buzzing, go to step 6. If horns do not have a harsh tone or buzzing, go to next step.
- Repair high resistance in horn control circuit (Dark Green wire) or horn ground circuit (Black wire). After repair, go to step 7.
- Replace horns. After repair, go to next step.
- Operate horn to verify repair. If horns do not operate correctly, repeat test beginning at step 3.