1. Check the Horn Relay (if applicable):
* Locate the Relay: Consult your owner's manual or a wiring diagram for your specific Impreza model to find the horn relay. It's usually located in a fuse box (under the hood or inside the cabin).
* Swap the Relay: If you find a relay, try swapping it with a relay of the same type from a different circuit (if possible, and only if you understand relays and are comfortable with this process). If the horn works, you've found the faulty relay. If not, the problem lies elsewhere.
2. Check the Horn Wiring:
* Horn Button: The horn button itself could be faulty. With the ignition on, carefully test the connection at the horn button using a multimeter in continuity mode or a test light. You should see continuity when you press the button. If not, replace the button.
* Wiring Harness: Carefully trace the wiring from the horn button to the horn. Look for any breaks, loose connections, corrosion, or damage to the wire insulation. Repair or replace any damaged wiring. Pay close attention to the connections at both ends – the button and the horn itself.
* Ground Connection: A poor ground connection can prevent the horn from working. Ensure that the horn is properly grounded to the vehicle chassis. Clean the ground point if necessary.
3. Test the Horn Directly:
* Direct Power: With the ignition on, use jumper wires and a test light or multimeter to apply power directly to the horn terminals. Be careful to observe polarity (+ and -). If the horn sounds, the problem is in the wiring or the horn button. If it doesn't sound, the horn itself is likely faulty.
* Safety Note: When working with automotive electrical systems, always disconnect the negative battery terminal to prevent short circuits.
4. Steering Wheel Issues (Less Likely, but Possible):
* Clock Spring: On some vehicles, the clock spring (a spiral cable inside the steering column) provides electrical connections to the steering wheel. A faulty clock spring can interrupt the horn circuit. This is more common if the airbag light *was* on at one time.
* Steering Wheel Contact: There might be an issue with the contact points in the steering wheel itself where the horn button connects.
5. Airbag System (Very Unlikely):
While you state the airbag light isn't on, a problem within the airbag system *could* theoretically affect other circuits, though this is rare and would usually result in other symptoms.
Important Considerations:
* Wiring Diagram: A wiring diagram specific to your 1993 Subaru Impreza is invaluable for tracing the horn circuit accurately. You can often find these online through Subaru forums or repair manuals.
* Professional Help: If you're not comfortable working with automotive electrical systems, it's best to take your car to a qualified mechanic. Improper repairs can lead to further damage or safety hazards.
By systematically checking these points, you should be able to pinpoint the cause of your horn's failure. Remember safety first, always disconnect the battery's negative terminal before working on the electrical system.
