Ensure safety and visibility during dark days and challenging conditions.
At the end of each summer, smart vehicle owners begin to plan for the fall/winter months, especially in those areas where temperatures drop, the nights get longer, and necessary systems can freeze and fail. This is particularly true in the case of automotive lighting.
The winter months harbor all kinds of problems for your car’s lights, largely thanks to low temperatures and excess moisture. For example, the filaments in your headlight or fog light system can exhibit reduced lumens output as a result of freezing temperatures, which cause connectors to become brittle and weak. More commonly, an excess accumulation of ice and snow on the housing will obstruct the light’s throw distance and obscure the path ahead.
Other seasonal challenges to watch for are condensation build-up inside the electrical housings, lens damage due to cracking or grazing, and faulty wiring connections.
Now that you have a basic grasp of the symptoms relating to cold weather failures, let's dive into each critical system to see why those parts really matter – and how you can check them to ensure they’re in tip-top shape.
What’s What In Your Car’s Exterior Lighting System
To ensure overall driving safety, automotive lighting systems become critical during winter months. Here are the most important components involved, and why each system is necessary.
Headlights. Easy enough, these are the forward-facing lights on your vehicle primarily used for nighttime driving. They consist of low beam and high beam functionality, and limited illumination of either state leads to shorter light throw. If you can’t see an obstruction before it’s too late, you can’t avoid it.
Fog Lights. Fog lights are positioned low on the front bumper and are designed to cut through dense fog, rain, or snow, improving visibility in adverse weather conditions.
Tail Lights. Located at the rear of the vehicle, taillights serve to signal the vehicle's presence and indicate its direction of travel, especially during braking and turning. Always ensure that both your tail lights are working, since they make your car more obvious to others approaching from behind.
Brake Lights. Activating whenever you apply the brakes, these very important lights signal to following vehicles that your car is slowing down or coming to a stop. Obviously, working brake lights are vital during winter days of reduced visibility.
Turn Signals. These lights, located at the front and rear of the car, indicate a driver's intention to turn or change lanes. Ensure that all turn signals function effectively; if you can’t be seen, you’re just a moving target.
Hazard Lights. Also known as “flashers” or “emergency lights,” these lights are located in both the front and rear of a vehicle and, when activated, flash simultaneously in a synchronized pattern. During winter, it’s critical these are in good working condition, as they’re key to making your vehicle more visible during adverse conditions.
Reverse Lights. These white lights illuminate when the vehicle is in reverse, and
help you see when backing up.
Daytime Running Lights (DRLs). DRLs are low-intensity lights that automatically turn on during daytime driving to increase the vehicle's visibility to other road users.
Think you might be in need of new equipment? Check out our article on winter lighting upgrades.
Step-By-Step Exterior Checks
Maintaining your vehicle’s external lights is essential during winter operations. Check out this simple step-by-step guide to help you do a thorough check, plus a few handy tips to make it easier.
To start, turn on your vehicle without starting the engine. This will allow you to access the lights and other electrical systems, without running the engine. (In most push-start vehicles, this simply means pushing the ignition button without depressing the brake pedal. If your ride still uses a key, simply don’t turn it all the way.)
While you can do all these checks by yourself, it goes much faster if you have a friend or family member operate the lights while you inspect them.
Inspecting Headlights
First, take a look at the headlight housing itself. Look for any scratches, chips, or haziness on the lenses, as well as any deeper cracks or clear signs of damage. If present, consider picking up a headlight restoration kit or cleaner to polish/buff the lenses or replacing them if severely affected.
If you see signs of condensation – like fogging or droplets – you may need to remove the affected lights, dry them thoroughly, and seal any potential entry points for moisture.
Next, turn on the headlights and ensure that both high and low beams are working correctly. If one is not functioning, it may indicate a burnt-out bulb or an electrical issue.
Lastly, check that the headlights are properly aligned, not pointing too high or too low. The best way to do this is by observing the headlight beam pattern on a wall, preferably one about 20 feet away. The beams should be even and align horizontally with each other. There should also be a slight downward slope, with the light beams hitting the wall just below the horizontal centerline of the headlight housings. If alignment is off, consult your owner’s manual for adjustment instructions or consider having a professional mechanic take a look.
Inspecting Fog Lights
Start by visually inspecting the fog light housings. Again, you want to check for any cracks, damage, or signs of moisture.
Next, turn on the fog lights. (They are typically marked with a symbol that looks like a small, downward-pointing arrow or a stylized "F.") The lights should emit a bright, focused beam that is lower and wider than the main headlights. Check that both fog lights are on and producing the same level of brightness.
Since some vehicles allow you to adjust the angle of the fog lights, you may want to check alignment as well. Look for a beam that is not pointing too high or too low, and make any necessary tweaks based on your owner’s manual.
Inspecting Taillights, Brake Lights, Turn Signals, & Hazards
Walk to the rear of your vehicle and examine the light housings for any cracks, scratches, or other damage. You should also check for dirt or debris on the lenses, cleaning them if necessary.
Next, turn on your vehicle's headlights and then engage the parking or daytime running lights (if applicable). This will activate the taillights. Walk to the rear of your vehicle and visually inspect the taillights. You should see both the left and right taillights illuminated.
Then, have a helper depress the brake pedal (you can always place an object on it, if you’re flying solo) and observe the rear lights. Both taillights should become brighter when the brakes are applied.
Turn signals are next, checking for steady blinking after you or a friend activates each one in succession. If the turn signals flash too quickly or do not illuminate at all, it may indicate a burnt-out bulb or a faulty flasher relay.
Finally, test the hazard lights. Both taillights should flash simultaneously.
Inspecting Reverse Lights & DRLs
To check reverse lights, you will need to start the vehicle and shift into reverse. Look in your rearview mirror or have a helper stand behind your vehicle and watch for the illumination of the reverse lights. Typically located in the taillight housing, they should light up when you engage reverse gear.
DRLs typically activate automatically when the engine is running and the vehicle is in gear, so now is a great time to give those a once-over as well. While sitting in the driver's seat, look ahead and observe the front of your vehicle. The DRLs should be emitting a steady, low-intensity light.
Don’t Forget About Interior Lights
Fully-functioning dashboard indicators and interior cabin lights are also important during the winter. To ensure they’re in good working condition:
Examine the dome light for any signs of dimness or uneven lighting. Ensure that all lights turn on and off when the doors are opened and closed. If not, check bulbs and the door switches.
If your vehicle has map lights, inspect them for proper operation. Look for dimness, flickering, or malfunction.
Sit in the driver's seat and turn on the vehicle's ignition to ‘On’ without starting the engine. Check all dashboard lights for proper operation.
Inspect all interior light covers and lenses for dirt, dust, or smudges. Wipe them clean with a cloth or paper towel.
Cleaning & Maintenance Tips
Although we're mainly talking about winter driving here, it's crucial to regularly go over the basics of taking care of your car lights. In addition to performing the regular inspections detailed above, here’s what you need to remember:
Keep it clean. Use a clean cloth to wipe down light housings and remove dirt, grime, and road salt. Consider applying a protective coating to the lenses to extend time in between cleanings, and help prevent hazing or damage from UV rays.
Check bulbs. Replace any weak bulbs promptly. Check your vehicle's owner's manual for the bulb specifications.
Check electrical connections. Regularly check wiring and electrical connections for corrosion, loose connections, or physical damage.
Seal any cracks. If you notice any cracks or gaps in the light housings that could allow moisture to enter, seal them with a clear automotive silicone sealant. This helps prevent condensation and moisture-related issues.
Wipe off snow/ice. After parking your vehicle in snowy conditions, remember to give the light housings a quick clearing so it doesn’t ice up before you need to drive again.
Keeping your vehicle's lights in top condition during winter is essential for safe driving – but so is using them correctly! Remember to always turn on your headlights in low-light conditions, particularly during rain, and in fog or snow. Use high beams only when there is no oncoming traffic, and dim your lights when on-coming vehicles appear.
Similarly, only use fog lights in conjunction with low beams. Properly aligned headlights tend to reflect moisture particles in fog or snow, thereby creating an unhelpful glare. However, fog lights are aligned to direct their illumination lower, making it easier to see directly ahead.
Stay safe, stay visible, and enjoy your winter drives with confidence.