Chevy Silverado Fog Light Not Working – Why And What To Do?

Are you having problems with the fog lights of your Chevy Silverado, and do you want to know what is causing the problem? And would you like to know how to fix it? You’ve come to the right place, for we have researched this question, and we have the answer for you.

If only one of your fog lights is not working, then the problem could be a burned-out bulb. Replacing the bulb should fix the problem. Here are the possible reasons if both fog lights are not working:

  • Bad fuse
  • Faulty relay
  • Faulty switch
  • Wiring problem

Learn more about the different reasons why the fog lights of your Chevy Silverado are not working in the succeeding sections. We also included the different ways that you can fix each of the possible causes.

Read on!

CHICAGO, IL - FEBRUARY 11 2017 Chevy Silverado HD pickup at the annual International auto-show,Chevy Silverado Fog Light Not Working—Why And What To Do

What are fog lights?

Fog lights are a special type of light that helps visibility during low-visibility situations. They are non-standard equipment that is useful when driving during heavy rains, dust storms, and thick fogs.

And did you know that there are two types of fog lights?

Front-facing fog lights are normally found below the headlamps. Fog normally forms one to two feet above the ground. Thus, front-facing fog lights are closer to the ground than fog, and their light is angled downward.

Rear-facing fog lights, on the other hand, help other drivers to see your vehicle during low-visibility situations. They are red-colored lights that you can find in the middle of the rear bumper cover. They are rarely seen in the US, but they are mandatory in Europe.

When to use fog lights?

When to use fog lights - Driving in Dense Fog at Night. Modern Car on the Foggy Road During Night Hour

Fog lights are not a replacement for your regular headlamps. They are useful only for seeing road markings over short distances. Thus, they become useless at higher speeds.

Always use your fog lights with your headlamps. Despite their name, fog lights will not help you see through a thick fog.

When is it legal to use a fog light?

When is it legal to use a fog light - two blurred cars moving on empty night foggy road.

Fog lights are optional features that car dealers sell as an add-on to your vehicle. Thus, not every vehicle has a fog light. This is one of the reasons why you can find many aftermarket fog lights for Silverado.

However, before you decide to install an aftermarket fog light, check the traffic laws in your area to know what you can install.

Some states limit the color of the light beam of a fog light. Moreover, there are traffic laws in some states that specify situations where you can use fog lights and when you cannot.

What causes fog light problems?

A modern car with bright LED headlights—What causes fog light problems?

Fog light issues are often electrical in nature. Anything that disrupts the supply of electrical energy to the fog lights will prevent them from working properly. Thus, the first thing to check when the fog light stops working is the continuity of the electrical current to the fog light bulbs.

Let’s talk about each of these electrical components that complete the fog light circuit of your Silverado.

How to diagnose a burned-out bulb?

It is easy to diagnose a burned-out bulb if only one of the fog lights is not working. Although, both bulbs burning out at the same time can happen.

Another possibility is that you didn’t notice that the first fog light was not working because the second bulb covers the absence of the other one. It is easier to notice that the fog light is not working when both bulbs are burned-out.

Checking the bulbs is a good first step because all your efforts to find the problem with the rest of the circuit will be futile if the bulbs are not working.

Make sure that the engine is off and that the parking brake is active before working with the fog lights.

Get into the fog light housing and take the bulbs out.

Use a multimeter to check the bulbs. You should get a non-zero reading to show that there is electrical continuity within the bulb. A zero reading means that you need to replace the bulb.

SEALIGHT 6000K fog light bulbs are available on Amazon through this link.

How to check for a bad fuse?

How to check for a bad fuse - isolated, background, no people

The fuses inside your Silverado serve the same purpose as the circuit breaker inside your house. It protects the circuits of your car—including the wires and the electrical equipment—from an electrical surge.

Fuses protect the electronic devices in your Silverado by burning themselves out once there is an electrical surge. A burned-out fuse will no longer allow the flow of electrical energy through that circuit.

Thus, to get the circuit working again, you will need to replace the fuse.

Check your owner’s manual to find out the location of the fuse box. Once you find the fuse box, check the manual once more to get the location of the fuse for the fog light.

Check the fuse for any signs of damage. The filament inside the fuse should be intact for the fuse to work. Replace the fuse if it has signs of damage or if the filament is broken.

CrocSee car fuses assortment kit is available on Amazon through this link.

Car Circuit Breaker

When replacing your fuse, you have the option to install a car circuit breaker instead of a regular fuse. The circuit breaker can be reset after an electrical surge trips it. It saves you a trip to the automotive shop for a new fuse.

Gloaso circuit breaker is available on Amazon through this link.

How to check for a bad relay?

A relay is often found with the fuses in the same box. If it is not in the same box, check the manual to find the location of the relay that you need.

A relay is responsible for allowing a small electrical current to control the circuit that requires a large electrical current. This is important because most of the electrical components in your car use low electrical current, while certain electrical devices—like some fog lights—require a large electrical current.

Electrical components that work with large currents need a relay to “relay” the command from the low current side—usually a switch. Without a relay, the high electrical current will burn out the circuits that use a low electrical current.

A relay works by generating a magnetic field when you turn on the switch to your fog light. The magnetic field will pull a switch to complete the circuit for the fog light. Without a relay, your fog light will not turn on.

Checking a relay can be done with a multimeter. Set the multimeter to “Ohms” and then look for pin number 85 and pin number 86. Touch these two pins with the tester and check the reading.

A working relay will have a minimum of 50 Ohms. Anything lower than 50, and you need to replace the relay.

How to check for a faulty switch?

The switch controls the flow of electricity to your fog light. If the switch starts to fail, it can become stuck open and will not be able to let electrical current reach your fog lights.

If you suspect that the switch is the problem, you will have to replace it.

Pry the fog light switch from the dashboard and disconnect the wire harness. Connect the wires to the new switch, then install the switch on the dashboard.

A fog light switch for 2003 to 2007 Silverado is available on Amazon through this link.

How to check for a wiring problem on the fog light?

A worn-out or chewed-on wire can prevent electrical energy from reaching the fog light. This can happen anywhere from the wires coming from the fog light’s switch to the fuse box and to the fog lights.

It can take a long time to test the wires in your Silverado, and you might not be able to find all the right wires.

In this case, it is best to bring your Silverado to a mechanic to check the wires. This is a good idea if you’ve already replaced the components above, but the fog lights are still not working.


There are several reasons why the fog lights on your Chevy Silverado are not working. Start checking the possible causes in the same order above until you get to the real cause of the problem.

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