Hello Paul, my car’s horn sometimes honks faintly on its own when I drive over potholes. Could this be a wiring problem in the steering column or a fault with the airbag system? Is it safe to continue driving until I fix it, or could this trigger the airbag unexpectedly? Patrick
Hello Patrick, it can be irritating and embarrassing when your car horn honks unexpectedly while driving over potholes. Your concern about this issue is valid, as it is often caused by a faulty horn switch circuit that is connected to the driver’s Supplementary Restraint System (SRS) airbag in the steering wheel. These two circuits are housed in a component called the clock spring or spiral cable.
To explain further, the horn switch and driver airbag module are located in the steering wheel. The clock spring sits between the steering wheel and the steering column, providing the electrical connections for the horn, airbag, and steering controls while you drive. When you drive over potholes, a loose contact in the horn switch or damage to the spiral cable can lead to unexpected, albeit faint, honking.
Other less likely causes of random faint honking could include a loose horn button cover in the steering wheel, which may be dislodged or lose its insulation, resulting in unintentional honking. Additionally, a faulty horn relay or a poor ground connection can also trigger the faint honking as you drive.
Although you might be able to drive your car for a short time with this issue, it is not advisable to continue doing so. The faint honking is not only embarrassing but can also be an inconvenience to other road users.
While the risk of an unexpected deployment of the driver airbag is low, it is not completely out of the question, as an electrical short in the airbag spiral cable could potentially trigger it. Furthermore, driving with an SRS fault light is concerning, as it indicates that the driver’s airbag may not deploy when needed.
You should consult a qualified mechanic to diagnose the horn circuits and determine whether the short circuit is due to a faulty horn button, clock spring, or horn relay. If you see an airbag SRS warning light, a computer diagnosis will help confirm whether you need to replace the clock spring.
To prevent premature damage to the clock spring or horn/airbag spiral cable, avoid making aggressive, extreme turns of your steering wheel while stationary. When performing steering system repairs, the steering wheel should be locked to prevent it from spinning beyond its recommended limits, which can damage the clock spring.