Symptoms of a Bad or Faulty Fog Light Relay

Common symptoms include relay clicking sound and fog lights that either won't turn on or turn off.

The fog lamp relay is an electrical relay that is responsible for controlling the power to the fog lamps. Fog lights are lamps below headlights designed to improve visibility in dense fog or rain. They are designed to help the driver see the edges of the road in poor visibility conditions. When the fog lamp relay fails or has any problem, it can cause problems with the fog lamps. Usually, a faulty or failing relay will cause several symptoms that may alert the driver to a potential problem.

1. Click from the relay

One of the first signs of a problem with the fog lamp relay is an audible relay click. Many relays make a quiet audible click when turned on, however an excessively loud click may indicate an internal problem with the relay.

2. Fog lights always on

Fog lights that stay on all the time is another sign of a problem with the fog light relay. If the fog lamp relay shorts internally or there is any wiring problem, it can cause the fog lamps to stay on all the time. This is obviously a problem, as it drains the car's battery and also greatly shortens the life of the bulbs.

3. Fog lights do not turn on

Another common symptom of a bad fog lamp relay is fog lamps that don't light up. The fog lamp relay is the switch that controls the power to the fog lamps and it is usually controlled either automatically by the computer or manually by the driver. If the relay fails, it will cut power to the fog lights and render them inoperable.

Although fog lights are not normally used in normal driving conditions, they are useful in conditions of poor visibility, such as during heavy rain or dense fog. If you suspect that your fog lamps or relay may be having problems, have your vehicle checked by a professional technician such as AvtoTachki to determine if the vehicle needs a fog lamp relay replacement.