The car horn is generally located behind the bumper and accessing it can cause issues, such as broken screws or wiring problems. Although the circuitry for a horn is relatively simple, there is a chance to incorrectly adjust the wiring and create a short circuit.
The bumper cover is held on by several screws and clips located under the car, in the wheel well and engine compartment. There is always a chance, especially on older vehicles, to strip the mounting bolts. Once stripped, the thread must be drilled out and replaced. Although these problems can occur, there is a small chance as replacing a horn is a relatively simple procedure.