If your car horn is not working, take a few minutes to go over these common problems and what you can do to fix it yourself.  

Common Causes

The most common problems that will cause your car horn not to work are either the horn itself is bad or the clock spring mounted behind the steering wheel is bad. When the clock spring is bad it is very likely that your airbag or SRS warning light comes on at the same time. 

Why your car horn is not working:

  • Blown fuse
  • Relay
  • Damaged wire 
  • Defective horn
  • Faulty clock spring

 

In the next section, you will find several steps to help you figure out why your car horn is not working. 

Troubleshooting Steps

what to do if your car horn not working Fixing a horn that doesn't work is relatively easy and there are tests you can perform yourself. To fix your horn, you will need a few basic tools such as a digital multimeter. 

A retractable test leads such as can come in handy to test the horn.  

 

Check Fuses

 

One of the most common problems that can cause your horn to stop working is a bad fuse. Check the horn fuse to make sure it's not blown. The fuse box will be either on the side of the dash on the driver's side or in the engine bay.

If you have difficulty locating the fuse box for your particular car model look it up in your owner's manual. 

Look at the fuse chart on the back of the fuse cover or the owner's manual. You should see a fuse that says HORN. 

Pull the fuse and inspect the wire. If the fuse is blown replace it with a new fuse that has the same rating. 

Bad Clock Spring

horn doesn't work anymore

The clock spring is quite often the problem. What is a clock spring you may ask. 

A clock spring is a device installed right behind your steering wheel. It allows the airbag and horn wires to stay connected when you rotate the steering wheel. 

You will need to remove the steering wheel to replace or test the clock spring. Clock springs can be purchased online for any make and model and are inexpensive.

Check Horn Relay

common causes that can make a car horn not work

Locate the horn relay. The horn relay is found in the main fuse box located in the engine compartment

test horn fuse check horn relay

Use a multimeter to test the horn relay.  If you aren't comfortable with testing a relay, you can try this old trick. Find another relay on the fuse box that is identical to the horn relay. Let's say the fog lights relay is identical. Switch the two relays. 

  • If your horn works but the fog lights don't, that means the relay is defective. Replace it.
  • If the fog lights work, that means the horn relay (now installed for the fog lights) is good. 

Direct Feed the Horn

install a new horn if old is dead

If you haven't had any luck with fixing the horn, we need to check if the horn itself is working. Locate the horn which is mounted near the radiator. The horn is usually between the radiator and the front grill. It will help to remove the front grill which is held in place with a couple of screws. Some models may require that you remove the front bumper to get to the horn. 

Unplug the electrical wires that go to the horn. Do you have two wires going to the horn or just one? 

If your horn has two wires one of them will be brown or black. This is the ground wire. You can connect the horn negative terminal directly to the body of the car or connect it to the battery negative terminal which will serve as our negative feed. 

Next, use a +12 volt feed line from the battery positive terminal to the horn. When you touch the horn terminal, you should hear the horn beep. 

    Horn does beep
    • The horn itself is good. Move to the next step to troubleshoot why the horn isn't getting power. 
  • Horn doesn't work
    • If you don't hear the horn that means the horn is defective. Replace the horn. If the fault is on the horn itself, you may be able to dismantle the horn and find what is wrong. Cleaning the contact breaker might work. There might be a broken or disconnected wire inside. New horns are very inexpensive costing as little as $20 USD. A 12-voltrsal car horn will get the job done even if you have a newer car.

Watch a video on how to install a new horn if yours doesn't work.

Check Voltage at Horn

 

Next, we will check for power at the wires that plug into the horn. 

  1. Set your multimeter to measure DC. 
  2. If only one wire goes to the horn.
    1. Connect the black lead wire to the body of the vehicle and the red to the wire that you unplugged from the horn. 
  3. If two wires go to the horn. 
    1. Connect the black lead to the brown or black wire. Connect the 
    2. Connect the red lead to the red/power horn wire. 
  4. Turn the ignition to ON and have your friend press on the horn. 
  5. Read the multimeter. You should get 11 to 14 volts when the horn is pressed. 

If you don't get any power at this point, check the horn wire harness. Often you will see that the plug itself is corroded. 

 

Check Wire Harness

how to fix a horn problem

If the horn works, but you are not getting power to the horn itself check the wire hraness. You may also find that the plug may be loose or disconnected from the socket, as shown in the following picture. 

Check Ground

diy horn troulbeshooting

Many horns use the mounting brack to ground to the vehile. This serves the purpose of returning current to the battery or as negative termnial. It is common to stop working becasue there is no gorund or it is corroded.

Check the ground connection where the horn mounts to the frame. Often you will see corrosion here. Remove the horn and clean the corrosion. This is important because horns that use only one feed line will use the mounting bracket as the ground connection. If there is corrosion at this point, this may be the reason why your horn doesn't work. 

FAQ

My horn works but is weak.

  • If your horn sounds weak, clicks or sounds funny the issue usually is the horn itself. In such cases replacing the horn will fix the problem.  

My Horn doesn't work, and airbag light is on

  • This problem points to a defective clock spring. The airbag light stays on constantly. When the clock spring fails your airbag / SRS light will turn on in your instrument cluster. If you scan the fault codes for the airbag, you may find an error code that points to the driver's airbag. You can use an airbag scanner to retrieve the error codes by plugging it into the OBD-II port.  

Why is important to fix your horn? 

  • If your horn fails, you are left without an audible warning system. Therefore you will not be able to alert other drivers or children on the road and therefore you may not be able to avoid an accident. 

Driving without a horn is illegal in many states. When you get your car state inspected one of the components that are normally checked is the operation of the horn. If the horn doesn't work you will fail state inspections. 

Is it illegal to drive without a horn?  

  • In many states, yes. Check with your state MVA/DMV to verify if disconnecting the car horn is against the law. 

How can I disconnect the horn on my car? 

  • To disconnect the horn locate the fuse for the horn in the fuse box. Remove the fuse. The car will still operate normally without a horn. You can also remove the horn relay. You can disconnect the wires from the horn as well. Any of these methods will disconnect your horn and render it inoperable. 

My horn won't stop honking. 

  • To fix a horn that won't stop honking you may need to replace the horn relay.  If that doesn't work then most likely the horn button/switch which is part of the airbag is stuck and making continuous contact.

Remove the airbag and inspect it. The last possible cause is a damaged wire harness which could happen if your car was in an accident. 

Category
Electrical System