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Recently, some customers have told us that their LED headlight bulbs keep going out.
This can happen for a few reasons – like a faulty bulb, wrong installation, or even moisture inside the headlight.
But from what we’ve seen, the most common issue is a blown fuse caused by the LED drawing more power than expected.
If you discover a blown fuse after installing LED headlights, do not continue driving or replace it with a higher-amperage fuse, as this poses safety risks.
In this guide, we’ll explore the reason behind this common headlight problem in detail and provide best solution.
Table of Contents
Why Installing LED Headlight Bulb Burn Fuse?
We’ve discovered that when installing LED headlight bulbs especially above 55W it will easily cause fuse burning. Here is the main reason why installing high-power LED car lights may burn the fuse:
💡 High-power LED headlight bulb has nearly double the power of the original one, the factory-installed fuse may not be able to handle the increased current and can easily blow. In addition, high-power LED bulbs demand more voltage, which may affect the performance of other electrical components in the car.
Other Reasons:
◾ Poor Quality or Faulty LED Drivers – Cheap LED headlight bulbs with unstable drivers or no thermal management can cause current fluctuations.
◾ Incorrect Wiring or Reverse Polarity – If wiring isn’t properly connected (e.g., positive and negative reversed), a short circuit may occur.
◾ Electrical System Not CANbus-Compatible – High-power bulbs in a non-upgraded electrical system may lead to overload and overheating, causing the fuse to blow.
How to Fix a Blown Fuse After Installing LED Headlight Bulbs?
If your fuse keeps blowing after upgrading to LED headlights, don’t worry—here’s how you can fix it:
💡 Replace the Fuse with Correct Amp Rating
Only replace with the same amperage rating, never use a higher amp fuse.
💡 Use a Lower Wattage LED Car Bulb
Recommend using bulbs under 55W, which are safer for most stock fuse circuits.
How to Choose the Right LED Headlight Bulb That Fit My Car?
Not sure if your fuse is strong enough for that LED headlight bulbs?
Before checking the table, you should first check the ampere rating of your car headlight fuse, so you can match the correct fuse amperage with the right LED headlight bulb wattage your car can safely handle.
Check your car headlight fuse amperage corresponding to the highest power reference that can be installed
Original Car Fuse (A) | Recommended Max Power |
|---|---|
10A | LED headlight bulb no exceed 50W/bulb |
15A | LED headlight bulb no exceed 75W/bulb |
20A | LED headlight bulb no exceed 100W/bulb |
25A | LED headlight bulb no exceed 125W/bulb |
[Remark: The above data is for reference only. The actual situation is related to the year of the car, the material of the car’s lines, and the degree of aging.]
💭How Did We Come To The Above Conclusion?
“we recommend keeping the LED headlight’s current draw within half of the fuse’s rated capacity for safety. In real-world use, power increases can lower voltage and raise current. Whether it causes issues depends on the vehicle’s wiring—older or weaker lines may struggle, so we always factor in a 20% safety margin.”
Formula used: (Fuse Amperage ÷ 2) × 12.5V, then subtract 20% for safety margin
Therefore, we can get the following results:
Fuse Rating | Theoretical Max Power | After 20% Safety Margin | Recommended Max Power |
|---|---|---|---|
10A | (10 ÷ 2) × 12.5V = 62.5W | 62.5W – 20% = 50W | ✅ Do not exceed 50W |
15A | (15 ÷ 2) × 12.5V = 93.75W | 93.75W – 20% = 75W | ✅ Do not exceed 75W |
20A | (20 ÷ 2) × 12.5V = 125W | 125W – 20% = 100W | ✅ Do not exceed 100W |
25A | (25 ÷ 2) × 12.5V = 156.25W | 156.25W – 20% = 125W | ✅ Do not exceed 125W |
⚠️Warning: Don’t Use a Higher Amp Fuse Just to Install High-Power Products!
When upgrading your headlights or other electrical parts to higher-power products, it might seem like a quick fix to simply replace the fuse with one that has a higher amperage rating. However, this is very dangerous and not recommended!!!
Fuses are designed to protect your vehicle’s wiring and components by breaking the circuit if the current gets too high.
If you use a fuse with a higher amp rating than what your car’s wiring can safely handle, it won’t blow when it should, which can cause the wires to overheat. This may lead to damaged wiring, electrical fires, or even serious vehicle damage.
Instead of just upgrading to a bigger fuse, make sure to:
🟢 Replace with lower-power LED headlight bulbs that match your vehicle’s original electrical specifications.
🟢 Check the power rating of your new parts and ensure the fuse rating is appropriate and safe.
🟢 If you’re unsure, consult a professional to avoid risking your car’s safety.
Remember, fuses are safety devices, not power boosters. Protect your car and yourself by always using the correct fuse rating.
How To Know The Ampere Rating of My Headlight Fuse?
Step 1: Find The Location of Fuse Box
Most cars have two fuse boxes. One is located under the hood and is responsible for protecting the external electrical components such as the ECU, windshield washer pump, headlights, horn, ABS, and other systems. The other is usually found on the left side of the steering wheel inside the cabin.
Therefore, we need to open the hood of the car and find the fuse box with obvious signs.
Step 2: Understanding Car Fuse Diagram
A car fuse diagram shows which fuse controls each electrical part of your vehicle, like headlights.
It’s usually found on the fuse box cover and helps you quickly identify and replace the right fuse when issues occur.
Step 3: Find The Fuse That Corresponds To The Headlight
Check the fuse box diagram (usually on the cover) to find which fuse controls the headlights. Match the symbol or label like “LO BEAM”, or “HI BEAM” to locate it.
From the picture we can see that the fuse of the high beam and low beam is 15A.
Always Replace With the Same Amp Fuse
Using the wrong fuse can damage your car’s electrical system. That’s why it’s important to always replace a blown fuse with one that has the same amp rating. This ensures safe operation and prevents wiring issues or fire hazards.
Below are the steps to properly replace your headlight fuse.
Step 1: Find The Location of Fuse Box
Step 2: Carefully refer to the diagram to find the headlight fuse
Step 3: Use tweezers to remove the fuse and replace it with a new one.
⚠️Notice: Always make sure to replace the fuse with one of the same amperage as the original. Never use a fuse with a higher amp rating just to support high-power LED bulbs.
How to Check If a Car Fuse is Blown?
Method 1: Using a Test Light
Step 1: Insert the key and turn it to power on the vehicle (do not start the engine).
Step 2: Clip the negative lead of the test light to a grounded metal part of the car. Touch the tip of the test light to the metal contact points on the surface of the fuse.
✔️ If the light turns on, the fuse is good.
❌ If the light doesn’t turn on, the fuse is blown.
Method 2: Using a Multimeter
Set the multimeter to the continuity or circuit test mode. Place one probe on one side of the fuse and the other probe on the opposite side.
✔️ Fuse is OK: The multimeter beeps
❌ Fuse is Blown: There is no beep
Method 3: Visual Inspection
Check the fuse by visual inspection. If the metal strip inside the fuse is broken or burned, the fuse is blown. If the strip is intact, the fuse is still good.
Top 3 Low-wattage LED Car Lights To Protect Your Car
Concerned about high-power LED headlight bulbs overloading your vehicle’s fuse?
To ensure both safety and performance, we’ve curated a list of the top 3 recommended low-wattage LED headlight bulbs. These options are engineered to deliver high brightness with low power consumption, making them ideal for vehicles with sensitive electrical systems.
3 Colors Fit All Weather NAOEVO S4PRO 30W 3600LM/Bulb 
| Unique Bullet design NAOEVO S3MAX 45W 5000LM/Bulb 
| Excellent Beam Pattern NAOEVO XGT6 60W 7200LM/Bulb 
|
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