Did you know that vehicles in Georgia must have a working horn? According to Georgia Code Title 40 – Motor Vehicles and Traffic, “Every motor vehicle when operated upon a highway shall be equipped with a horn in good working order and capable of emitting sound audible under normal conditions from a distance of not less than 200 feet…”
If your car horn has honked its last honks, don’t worry—fixing a broken car horn is usually a fairly simple repair. With used auto parts from U Wrench It, a little research, and some elbow grease, you can have your car street legal (and loud) again in no time.
How to Fix a Broken Car Horn
Find your fuse box and check for a blown fuse.
Get out your owner’s manual (or if you don’t have it, look for a pdf online) and locate the fuse box. In most cars, it’s on the driver-side dashboard. Using the fuse box diagram or manual key, find the fuse for the horn and use fuse pliers to pull it out. You should be able to see through the clear casing whether the fuse is blown; if it is, the wire connecting the prongs of the fuse will be broken.
If the wire isn’t broken, use a multimeter to test the fuse. If the reading is “out of limits,” the fuse needs to be replaced. If the reading is a number, your fuse is fine and you’ll need to keep searching for the problem.
Check the relay and relay switch.
Open the relay box under the hood and find the horn relay. Remove it and replace with another relay of the same type. Test the horn. If it works, you need to replace the horn relay. (Don’t forget to put the good relay back where you found it!)
If you still haven’t solved the mystery of the silent horn, move on to testing the relay switch. For this, you’ll need an assistant. Take the relay out and touch one of your multimeter probes to the relay socket. Touch the other to the negative node of your car battery. While maintaining this circuit, your assistant should try to honk the horn. If your multimeter reads “out of limits,” you need to replace the relay switch.
Test the car horn.
Check behind the grill of the car for the actual horn. To do this, you’ll need to use your car battery and jumper wires to test the horn. Be careful—you don’t want to get shocked—and follow instructions carefully.
Examine the horn switch.
If you’ve tried all of these things and still haven’t found the problem, there could be one more explanation: The horn switch. This step involves removing the steering wheel pad, which is a bit more invasive than the other tasks so far. If not done correctly, it could make your airbag less effective or disable it altogether. Depending on your level of experience, this is one car repair job you may want to leave to the professionals. However, even if you end up taking your car to a shop, remember that you can buy your own used auto parts or request that they buy used parts to save on the cost of the repair.