How to Fix a Car Horn

You’re on your way to work and all of a sudden - a driver on his cellphone pulls out in front of you. You go to honk your horn but nothing happens. You quickly pull into the opposite lane, barely avoiding a collision. Not having a functional horn could have costed someone’s life.

Typically, the horn circuit consists of the horn, switch, fuse, and relay. Battery voltage is applied through a fuse to the relay winding and contacts. When the horn switch is depressed, the relay is grounded, completing the circuit and blowing the horn. Some vehicles do not use a relay, and voltage is supplied directly through the horn switch to the horn. In this article, we will go over how to test and repair each of these components. Here is how to fix your car horn:

How to Fix Your Car Horn

  1. Gather the correct materials - To properly fix your car horn, you will need the following: Digital multimeter, Jumper wires (optional), Multimeter, Protective gloves, Quick-disconnect connectors (optional), Repair manuals (optional), Safety glasses, Wire crimping and stripping pliers (optional), and some Wire (optional).

    fuse box cover open

  2. Locate the fuse box - You first need to test the fuse and relay. The location of the fuse can be found in your owner’s manual. Generally, there is a fuse box on the driver’s side of the dash and one under the hood of the car.

    Tip: AutoZone provides free online repair manuals for certain makes and models. You can visit their website to see if a free manual is available for your car.

    car horn fuse in diagram

  3. Find the right fuse - Look at the diagram on the back panel of the fuse box and find the fuse number that corresponds to the horn.

    Tip: You can also check your manual to see the fuse diagrams for each of your fuse boxes.

    person removing fuse with pliers

  4. Remove the fuse - Once you have located the fuse for the horn, pull it out with either your fingers or a pair of fuse pliers.

    blown fuse and new shown side by side

  5. Check the fuse - In order to check whether or not the fuse is your problem, you will need to inspect the fuse to see if has blown. If the U-shaped wire is broken, the fuse has blown and will need to be replaced. If the wire inside is not broken, this does not ensure that the fuse is still working.

    checking fuse with a multimeter

  6. Test the fuse with a multimeter - Test the fuse with a multimeter. You can do this by turning on the multimeter and touching one meter lead to each of the fuse’s terminals. You should get a numeric reading on the meter screen. If, however, you get a reading of saying “Out of limits (OL)”, there is no continuity and the fuse is blown.

    installing new fuse back into fuse box

  7. Install the new fuse - If you find the fuse has failed, install a new one of the same amperage rating. To do this, simply push the fuse back into its correct slot.

    Note: Keep in mind, fuses don’t blow for no reason; they blow in order to protect the circuit from excessive current draw. Keep an eye on any new fuses that are installed. If it blows again, you will need to inspect the circuit for faults.

    underhood fuse box

  8. Locate your relay box - If the fuse checks out OK, the next thing you’ll want to do is check the horn relay. The relay location will be listed in your owner’s manual. Generally, it will be found in the underhood fuse box.

    identical brown fuse relays

  9. Test the relay - The easiest way to check for proper relay operation, is to swap the horn relay with another identical relay in the vehicle. Typically, the same relay design will be used on a few different circuits, allowing the relays to be swapped within a car. If the horn functions with the alternate relay installed, you know the relay is the problem and should be replaced.

    Open steering wheel

  10. Remove the relay and set up your meter - Using the repair manual for your vehicle, to determine which relay terminal is controlled by the switch. Most relay switches will be found inside the steering wheel. This will require opening the steering wheel by accessing the two screws on the left and right sides of the steering wheel.

    removing steering pointed out on both sides

    Warning: The horn switch is usually part of the steering wheel pad. In modern vehicles, this means it is part of the airbag system. Improper service of the airbag system can result in accidental airbag deployment and/or damage to the airbag system. So, if you suspect a faulty horn switch, it is advisable to have the repair performed by a professional.

  11. Test the horn switch - If there is no power at the horn switch, then the button will no longer respond when the button is pressed.

    multimeter with ohms set

  12. Test the relay switch - Remove the relay and set your digital multimeter to the Ohms setting. Touch one meter lead to the switch relay socket and the other to the battery negative post. Have another person push the horn button to test the reading.

    Tip: You should see a numeric reading on the screen indicating continuity. A continuous reading displaying “Out of Limits (OL)” means that the switch is not closing and needs to be replaced.

    using multimeter on car

  13. Test the horn - You can find the horns of a car on the radiator core or right behind the car’s grille.

    hand reaching out to car horns under hood

  14. Determine which wire is power and which is ground - Using the factory repair manual for your vehicle, determine which wire is power and which is ground.

    car horn hooked up to battery

  15. Jump the horn - Remove the horn connector and attach a jumper lead between the battery’s positive post and the (+) terminal on the horn. Then, connect the other jumper wire between the negative battery post and the (-) terminal on the horn. The horn should now sound. If it does not, the horn is faulty and should be replaced.

  16. Test the circuit - If your horn still does not work after you have tried all of the methods above and replaced all faulty components, then the last thing that you can check is the horn’s circuit.

    checking power of a horn connector

  17. Check the wiring - If everything checks out to this point, but the horn still does not work, you’ll want to check the circuit wiring. Test the ground side of the circuit and the power side for current and voltage in the steps below.

  18. Test the ground side of the circuit - According to your car’s manual, identify the ground side of the circuit. To check for ground, set the meter to the Ohms setting. Then touch one meter lead to the horn connector (-) pin and the other to the ground. You should see a numeric reading displayed on the meter lead if this is working properly.

    Tip: A reading of “Out of Limits” (OL) means there is no current to the horn ground. In this case, a professional will need to access the factory wiring diagram to trace the cause.

  19. Test the power side of the circuit - According to your car’s manual, identify the power side of the circuit. Check for power by setting your meter to the volts setting. Touch one meter lead to the horn connector (+) pin and the other to ground. Your meter should display battery voltage.

    Tip: If it does not display a number, a professional will need to access the factory wiring diagram to trace the cause.

If you’d prefer to kick back and relax while someone else fixes your horn, the team at YourMechanic offers horn diagnostics and repair. Calling a professional can save you time, money, and frustration. If needed, our mechanics can replace your fuse, relay, switch, or horn so that you can safely venture on the road.

Next Step

Schedule Horn does not blow Inspection

The most popular service booked by readers of this article is Horn does not blow Inspection. Once the problem has been diagnosed, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. YourMechanic’s technicians bring the dealership to you by performing this job at your home or office 7-days a week between 7AM-9PM. We currently cover over 2,000 cities and have 100k+ 5-star reviews... LEARN MORE


The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Recent Horn does not blow Inspection reviews

Excellent Rating


Rating Summary


40 years of experience
783 reviews
40 years of experience
Hyundai XG350 V6-3.5L - Horn does not blow - San Mateo, California
Nissan Pickup - Horn does not blow - Santa Clara, California
I have been a dedicated customer with 'Your Mechanic' for a few years. As always, I received a professional and courteous experience from, Whitney. As a grandmother it is important that my vehicle is running well. Suffice as to say, as a woman, it took me more than 15 years to find a honest, trustworthy, mechanic. I have found that in Whitney and in your organization. It is a pleasure doing business with your organization and to refer people. I hope you treat your employees with the same courtesy they have shown us. Thank you for my receipt. Rosanna 11.06.2015


27 years of experience
828 reviews
27 years of experience
Nissan 350Z V6-3.5L - Car idle is rough - Campbell, California
Honorio arrived 10 minutes early which was great. He was very professional, friendly and very knowledgeable. He found the problem on my car within minutes!! I was very impressed with the knowledge he has for car. To me he is an expert on what he does. He will show you and explain what the problem is, Honorio goes above and beyond. It's very hard to find a mechanic you can trust. I just found my mechanic. Thank you Honorio for showing and explaining to me what the root cause of the problem was. Your customer service is the best I've ever experienced!!
Chevrolet Impala - Axle / CV Shaft Assembly Replacement (Passenger Side Front) - Campbell, California
Honorio continues to do a great job. He's been working on my 2001 Chevy Impala making various repairs over the last 2 months. He's always on time, reliable, and competent. It is so convenient to have him come out to the house. The prices are very reasonable, too. Now that he's got the Chevy all fixed up, I'm going to ask him to work on my 1979 Pontiac Firebird. Actually, Honorio is the only person I want working on my vehicles. I only go to the shop now if there is something that can't be done mobile.


23 years of experience
2372 reviews
23 years of experience
Toyota Tacoma V6-4.0L - Horn does not blow - Huntington Beach, California
Very nice and quick!!!


28 years of experience
333 reviews
28 years of experience
Pontiac G6 V6-3.5L - Horn does not blow - Washington, District of Columbia
Overall great experience. Very knowledgeable, patient and willing to explain the process step by step.

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.


Related articles

How Long Does a Horn Relay Last?
Having Having a fully functional horn is an essential part of staying safe while driving. The horn on your vehicle will allow you to alert other drivers of your presence and can be used to prevent accidents in some instances....
How to Turn Off a Car Horn
If If you’ve ever heard a car horn ( honking for hours, you’ll know that the experience is anything but pleasant. Not only does a constantly running car horn cause annoyance to you and your neighbors, but it can actually...
How to Check Your Car Brake Lights
Car brake lights are essential for driving safely. Check the brake lights and brake fuses regularly to keep the brake system working well.

Related questions

Headlights stay on
Hello. This sounds like the headlight switch is faulty. You might also want to check to make sure you have the headlight switch in either the auto position, or the off position. If the headlight switch is left in the...
Anti theft problem
Rarely will pulling a fuse disable an anti-theft system. If it were that easy, thieves would figure that out quickly and more cars would be stolen. Fortunately, most factory alarms are usually fairly simple to diagnose but very difficult to...
Car won't start and doesn't have normal power
Thanks for writing in today about the issue with your Saturn. Without being there to physically inspect the car, it's very hard to give you a precise diagnosis, but one common problem that occurs when people install accessory items like...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 ·