Fog lights are located beneath the headlights of the Toyota Tundra. You can turn these ON in foggy, rainy weather and at night for better visibility. These are present close to the ground surface and illuminate the road markings to ensure safe driving in low visibility conditions. Sometimes, they stop functioning and cause issues while driving during foggy nights.
Toyota Tundra fog lights not working can be due to their incorrect installation, damaged relay, blown-out fuse, damaged button, blown-out LED bulbs, loose wires, and corroded ground connections.
I also faced faulty fog light issues in my 2016 Tundra. I replaced the LED bulbs of the headlights and fog lights, and they stopped working after installation. I checked the fuses that are located in the engine compartment and under the dashboard.
I also inspected the fuses that had nothing to do with these lights but were fine. I realized that the issue came because of the failure of the relay, which was interrupting the current supply.
| Problems | Solutions |
| Incorrect installation | Correctly install fog lights |
| Damaged relay | Install new relay |
| Blown out fuse | Install fuse of correct amperage |
| Damaged button | Replace button |
| Blown-out LED bulb | Seal the protective coating or replace the bulb |
| Loose wires | Tighten or clean the electric wire connections |
Incorrect installation
Many people install fog lights as an aftermarket addition in their trucks because these are not factory-installed. The trucks have the wires and ports for the installation of these accessories.
You have to purchase suitable and compatible fog lights for your Tundra and connect them with the corresponding wiring connections.
Sometimes, they stop working when you install these as an aftermarket addition because of the incorrect installation. The problem comes when you install these without a mechanic.
You can also face issues when you do not connect their wires correctly. Loose mounting also causes an interruption in their normal functioning.
One of my friends also faced the same issue when he installed the fog lights in his Toyota Tundra last year. He said he turned on the switch, but the lights did not turn ON.
I recommended him to check the fuses, but he said all of these fuses are new. He checked the wiring connections, and those were not correctly installed.
He detached the wirings and got help from the owner’s manual for their correct installation. These were not functioning because incorrect wiring connections were not supplying sufficient current required for them. You can also hire an expert mechanic for their proper installation.
Damaged relay
Relays are the tiny devices that control the current flow to the fog lights. It regulates the sufficient current flow that is needed for their functioning.
These relays also become faulty like other components and do not allow the current to reach the respective components. These lights do not turn ON when you press their operating switch.
You cannot illuminate them because of the loss of power supply. Relay has a limited life span and can wear out because of its age.
In addition, it can also get damaged and stop working because of electric overload. A faulty electric system in the Toyota Tundra leads to an overloaded electric circuit and an interrupted current supply.
The issue also comes when you install relays of poor quality that are vulnerable to damage and have a short life span. These also come in exposure to heat, which can affect their internal components.
Corrosion can also come on relay terminals because of the presence of water and humidity. These relays are located in the fuse of the engine bay compartment.
Moreover, excessive vibrations and impacts from the engine compartment increase their risk of damage. It is necessary to inspect the relay when fog lights are not functioning. You can remove the corroded and damaged relays with new ones. Depending on their quality, you require $40 to $50 for their replacement.
Blown out fuse
Fog lights require a power supply from your truck’s electric source to function. It stops working because of a lack of power supply.
These contain fuses to protect their bulbs from blowing out because of power surges. Fuses blow out when they detect the electric changes in the circuits.
They blow out when a high current passes through the circuit and tries to reach the respective component. Replacement of a blown-out fuse is comparatively affordable and easy compared to the whole component.
These fuses protect these lights from malfunctioning, which usually occurs because of power surges and changes in current flow.
Fuse issues can also come because of shirt-circuited wires that cause hindrance in current flow. Blow-out fuses disable these lights and do not allow them to illuminate because of the absence of a power supply.
Moreover, corrosion causes the fuses to blow out. The problem in this part also comes because of the wear and tear with their age.
You can also face issues when you do not correctly install their wirings. Damaged or poorly connected wires cause short circuits and fuse blow-outs.
Issues in fuses come because of their incorrect installation. You can face problems when you install fuses that are not compatible with the corresponding electric component.
My friend faced an issue in his Toyota Tundra truck because of installing a non-compatible fuse. He selected the fuses with the correct amperage. Moreover, he installed it correctly without touching it because it increased their blow-out chances. It is better to inspect the electric wires when fuses blow out frequently because of short circuits.
Damaged button
The button for the factory-installed fog light is located on the turn signals. However, it is also present on the dashboard when you add them as an aftermarket addition.
These stop functioning because of the damaged buttons. Because of the damaged button, you cannot turn on the lights during foggy weather.
The damaged button does not activate the relays that control the power supply to these lights. In addition, many people accidentally turn them off and then become worried.
The fog light switch becomes faulty because of the failure of the turn signal stalk. These buttons can get damaged because of their normal wear and tear and age-related degradation.
In addition, corroded contact points of the switches also affect their normal functioning. You cannot turn these ON because of the corroded contact points.
Moreover, accidental impacts and water exposure cause failure of their internal components. You should also ensure that the operating switch on the dashboard or steering column is ON.
You can also replace the faulty switches with new ones and ensure their secure connection with electric wires.
Blown-out LED bulb
Fog lights have small LED bulbs that produce a sharp beam of light that is non-reflective. LED bulbs can blow out because of the excessive heat buildup from the engine and radiator.
In addition, they can also blow out when it comes to water exposure. The protective covering of these bulbs can break because of the degradation of plastic material and accidental impacts.
A damaged protective cover allows water intrusion. Dust and debris can also come in contact with these bulbs, increasing their chances of failure.
You should seal the damaged protective coating to decrease the chances of water intrusion and condensation on LED bulbs. It is also better to replace the blown-out bulb with a new one to turn the fog lights ON in your Toyota Tundra.
Loose wires
Fog light switches are connected with electric wires to illuminate the LED bulbs. They stop functioning, and you cannot turn them on because of loose wires.
Loose wires are not able to supply sufficient power to these lights. In addition, you can also face issues because of corroded and loose ground connections.
You should inspect the wires and clean the corroded ground connections by spraying electric cleaners on the affected area. Tighten the loosely connected wires in the Toyota Tundra to ensure smooth current flow.
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