If a horn is inoperative, what is the best practice recommended by the technicians?

When a horn is inoperative, the best practice involves checking both the status of the Supplemental Restraint System and assessing the voltage at the relay. Ensuring the functionality of the horn begins with examining the system as a whole, which includes electrical checks that are critical to diagnosing the fault.

By checking for voltage at the relay, technicians can determine whether power is reaching the horn circuit, which is a crucial step in troubleshooting. If there is no voltage, further investigation would be needed to trace the issue back to the power source, its connections, or the relay itself.

On the other hand, the Supplemental Restraint System could be connected to the airbag system, which may have safety implications. Disabling this system when necessary ensures that diagnostics can be conducted safely and without triggering any safety mechanisms.

Hence, performing both actions provides a comprehensive approach to diagnosing the issue, which is why taking both steps is recommended.