How to Replace a Horn Relayby David Grace
The automotive horn relay, an electromechanical switch, operates the horn. When you push the horn button on your steering wheel, you are closing a switch, allowing a small amount of current to the horn relay, which closes the main horn circuit. This circuit prevents the large current of the main horn circuit from traveling through the steering column, which could be dangerous. Like any electromechanical device, the horn relay can wear out and need replacement.
Find the section in the owner's manual that lists the location and function of each fuse and relay. It should tell you where to find the fuse box (typically underneath the steering column) and contain a diagram of the physical layout of the fuses and relays. Locate the horn relay in the list, and match it up with the appropriate location from the diagram.
Open the fuse box cover. A plastic clip usually holds the fuse box closed. You should now see the fuses and relays, in the same positions as shown in the diagram in the owner's manual. Find the relay in the fuse box at the location designated in the manual.
Remove the horn relay. Grasp the relay and pull it straight out of the socket. It should come out easily.
Insert the new horn relay into the socket. You will notice that it fits correctly only in the proper orientation.
Close the fuse box cover. Test the horn to make sure it works.
- If you don't have the original owner's manual for your vehicle, search online for your specific year, make and model. Many automotive manufacturers provide free downloads of owner's manuals.
Things You'll Need
- New horn relay
- Vehicle owner's manual
- Before you open the fuse box, turn the vehicle off and remove the keys from the ignition.
- Do not touch any metal inside the fuse box because of the possibility of shock.
- Be careful to pull the horn relay out and replace it without disturbing any other relays or fuses.
David Grace has been writing since 2009. His work regularly appears on eHow, drawing from his mechanical and automotive experience. Grace holds a Bachelor of Arts in Electrical Engineering from the Georgia Institute of Technology.