Turn off the engine. (Leave it off for the steps below as well. ) Wear insulated gloves and safety goggles. Remove all metal jewelry. Find a socket wrench that fits the terminal (typically ⅜ inches). Disconnect the negative terminal first. This typically has a - symbol and is connected to a black wire. Use caution to avoid creating a short with the wrench or wire. Disconnect the positive terminal.
If you do not have your car manual, search online for your make and model, followed by “manual” or “fuse diagram. " The fuse box is usually located under the driver’s side dash, in the driver’s side doorjamb, or in the glovebox. [4] X Research source Many cars have a second fuse box in the engine compartment. Some models, especially older ones, run several electrical components on the same fuse as the horn. Inspect the fuse diagram so you know what else will be affected.
Refer to the wiring schematic on the fuse box lid or in your owner’s manual to identify the correct relay. If your horn sounds different than usual or you do not hear the usual clicking sound when you press it, the relay is likely shorted. Replace it and try to discover the cause of the short, such as a damaged wire or water in the fuse box.
Many cars have two horns, but these are usually attached to the same unit. Refer to your owner’s manual wiring schematic if you are having trouble locating the horns. The battery must be disconnected while removing this part. Remove all jewelry and dangling clothing before reaching below the hood.
Always disconnect the battery first and wait at least thirty minutes for the power to drain from the airbag system.
