How to Wire Fog Lights to a Toggle Switch

Fog lights are a great safety feature for any vehicle, but it can be challenging to find a switch that allows you to turn them on and off.

Here is how you can wire your fog lights up to an existing toggle switch in your car so that you can control the light whenever needed! 

This blog post will teach you how to wire fog lights to a toggle switch so that they work with an existing toggle switch in your vehicle.

You will need some basic electrical knowledge and tools like a drill and screwdriver set.


Summary: Wiring fog lights to a toggle switch allows for easy control over their operation, adding convenience and safety during poor visibility conditions. To begin the process, gather the necessary tools and materials, including a toggle switch, a relay, wire strippers, crimp connectors, electrical tape, a fuse, and appropriately sized wires. Ensure that the toggle switch and relay are compatible with your fog lights’ voltage and current requirements to prevent electrical issues or damage to the components.

Start by connecting the positive wire from the fog lights to the relay’s output terminal, using a crimp connector to secure the connection. Next, connect a wire from the relay’s input terminal to the battery’s positive terminal, ensuring that an inline fuse is installed along this wire to protect the circuit. Then, connect the ground wire from the fog lights to a suitable grounding point on the vehicle’s chassis.

To wire the toggle switch, connect a wire from the relay’s control terminal to one of the switch’s terminals, and run another wire from the switch’s remaining terminal to a power source, such as the battery or an accessory power source in the fuse box. Finally, connect the toggle switch’s ground wire to a grounding point on the vehicle’s chassis. Once all connections are secure and insulated with electrical tape, test the fog lights by turning the toggle switch on and off to ensure proper operation.

Before starting the project or consulting someone who has previous experience with wiring or auto repair, I recommend reading through this guide if you are unsure about it.

Summary: Wiring fog lights to a toggle switch is a straightforward process that requires basic wiring and soldering skills. First, the ground wire needs to be connected to the fog light housing. Next, a power source such as an ignition-switched circuit should be spliced into the red wire of the fog lights. Lastly, the toggle switch should be wired in between the power source and the red wire of the fog lights and tested before being secured into place.

What Is a Toggle Switch?

A toggle switch is one type of electronic switch that you can move from one position to another. It has two positions, and often the other position activates something else, such as your fog lights.

It features a manually operated hind or handles mechanism called toggle. These switches are also known as “momentary” or “on/off” switches since you can only leave them in one position at any given time.

Instead, the toggle moves one position to another, and in each situation, it will lock into that place and remain there until moved back again.

What Are Fog Lights?

Fog lights are auxiliary lights that you install on your vehicle in the place of headlights. Fog lights are brighter than regular headlights, so they illuminate more surface area. 

This light helps drivers see better at night or during heavy rain, snow, and fog. Drivers can also use these extra lights to help them see better while backing up.

Why Use a Toggle Switch to Control the Fog Lights?

You may be wondering why you would want to use a toggle switch to control your fog lights. The truth is, it is much more convenient than having to remember where you plugged the wires into the light. 

This way, you can turn your fog lights on and off whenever needed without even thinking about them!


A toggle switch is also a lot more durable than other kinds of switches. You also won’t have to worry about accidentally turning your fog light on or off because it is in a place you will most likely never touch.

Steps To Follow: How To Wire Fog Lights to a Toggle Switch

Step 1: Find the Wire Harness

You can find the wire harness by looking behind your existing switch. The harness is followed by two black wires with small white markings on them. 

These are called color-coded wires, meaning they have specific colors assigned to some particular wires. So, for example, there will be an extra black wire without any white markings, but you can ignore that one. 

Step 2: Connect Both the Toggle Switch and Fog Lights Wire Harness

Next, connect the two harnesses with a wire connector by pushing them onto each other’s terminals until they snap into place.

Each terminal has two spring-loaded metal prongs on it, and another wire connector will have the same two prongs. You push them together, and they snap onto each other. 

Step 3: Mark the Wire Harness Wire Ends

At this point, you can choose to attach a wire connector to the black wire with white markings. This step is optional and depends on your personal preference.

Leave extra wire if you want to add more fog lights later or decide to use different toggle switches in the future. 

If not, cut off the excess wire from the harness and wrap it in electrical tape. It is best to make a mark on your wire harness to know which end goes where for future reference. 

Step 4: Wire Toggle Switch Wire Harness to Car Wire Harness

Now, go back to the rear of your vehicle, where the car wiring harness is located. If you are unfamiliar with the harness, there should be a diagram in the owner’s manual. 


If not, look for a bundle of wires that are routed through tubing along with your car’s frame. You can find the Wire connectors near this bundle, and you will need to remove the connector from each end to connect your new wiring. 

Step 5: Wire Toggle Switch Wire Harness Together

When you begin connecting wires, you want to make sure they do not touch each other or any metal parts.

You can use your clip-on wire stripper to remove insulation from the ends of each wire and then feed them through the clamps on both sides. Make sure that the colors on both sides match up. 

When they do, push the wire connectors into place until you hear them snap on. You can use electrical tape to wrap any leftover wire with a large enough diameter that it doesn’t touch anything or cover your wire connections from view. 

Step 6: Test Your Toggle Switch and Wire Harnesses

At this point, go back to the fog light switch and try flipping it on and off. If your new wiring harness was successful, the fog lights should go on and off as you open and close your new toggle switch. 

You can also use these steps to add more fog lights if you choose to go that route or even use the same ones just in a different location. 

5 Common Mistakes When Wiring Fog Lights and How to Avoid Them

Fog lights are great for off-road trails or help you see while driving on a dark roadway. The only problem is fog lights usually are not wired when installed, which means you don’t get the expected results.

Here are five common mistakes made when wiring fog lights and how to avoid them:

1) Wire is run under the hood through the firewall

When your wiring passes through a hole in the cab of the truck next to the firewall, you will have a short. 

There are gaps between the metal panels on your vehicle and many other small compartments where moisture can accumulate and ruin your electrical system. To avoid this, make sure your wiring is completely sealed in plastic.

2) Wire goes too close to the frame of the vehicle

The metal frame of your car has a lot of electricity running through it, so try to keep any wires away from it; otherwise, they could get damaged and catch on fire.


3) Wire is run underneath the bumper 

If your wiring is made out of metal, you’ll need to protect it by covering it in some plastic sleeve.

Otherwise, the wire will eventually begin rubbing on other parts of the vehicle and short circuit once it begins to wear through the insulation.

4) Wire is too close to the wheel well

All the rocks and pebbles will damage any exposed wires underneath the vehicle kicked up while driving off-road.

To avoid this, make sure you install some wire loom or tubing around the wires to keep them protected from harm.

5) Wire is close to the exhaust

When you wire your fog lights, try to make sure there’s at least an inch or two between them and the hot engine.

There are several different types of heat-resistant sleeves available for wiring that’ll keep it from becoming overheated.

Frequently Asked Questions

Why Do My Fog Lights Have 3 Wires?

Fog lights are typically connected to the vehicle’s battery, the engine, and the brake system. The brake system wire is used to activate the lights when the brakes are applied. The engine wire is used for illumination purposes and is often referred to as the “headlight” wire. The battery wire is used to provide power to the light fixtures.

How Do You Wire a 3-prong Toggle?

3-prong toggle switches are typically wired using a standard wiring diagram, which includes connecting the black (or common) wire to the black (or common) terminal on the toggle switch, the red wire to the red (or common) terminal, and the white wire to the white (or common) terminal.

Can You Run Fog Lights and Headlights Together?

Yes, it is possible to run fog lights and headlights together. However, it is important to consult with your vehicle’s manufacturer to see if this is recommended or not. Some vehicles may have specific requirements for the wiring and operation of fog lights and headlights, so it is important to consult with your car’s manufacturer before trying to install them together.


You now know how to wire fog lights to a toggle switch for your car. Fog Lights are an essential safety feature that helps drivers see at night when visibility is low. Wiring your fog lights to a toggle switch is easy. 

All you have to do is find the power wire for the light and then attach it with some wiring that will fit onto your new toggle switch. The wiring is elementary, and the installation can be done in just a few minutes. 

When you’re ready, use these instructions as a reference on how to do it yourself so that you don’t have to pay someone else or take your vehicle into an automotive repair shop! 

We hope this article was helpful teaching you how to wire fog lights up. If you have any questions or concerns, please don’t hesitate to contact us!

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