Why Does My Headlight Fuse Keep Blowing?

This is a question most vehicle owners must have asked at a stage after the purchase of their vehicle and in case you have not had an experience, expect it soonest. ‘Why do my headlight fuse and relay keep blowing ‘ is a question asked out of frustration, especially when you’re on the highway or recently had just fixed it. 

Just a reminder, a headlight fuse is meant to break and blow whenever too much power surges through them, this protects your vehicle and keeps something major from happening. Headlight fuse blows for many reasons and this post is to outline these reasons while providing a lasting solution to it.

What does it mean when the headlight fuse keeps blowing?

The Headlight fuse keeps blowing because they get too hot and tend to melt. So, you may have either of the following;

1. A resistance short: 

Your vehicle may have a short which you might not notice because the light still works, even though you might have a high resistance short. You can check it by disconnecting all the bulbs in order to measure the fuse terminal and ground, the resistance should be infinite. Another indicating factor of a high resistance short is that the bulb on the left may not be as bright as the one on the other side.

2. Too large a bulb for the light:

 This is the case with many fuses, the bulb may be too large for the light. To inspect this in order to know if it relates to you, try hooking up your meter where the short finder was, this should show about 5 Amps. But if it is up around 10 Amps, then it’s most likely to be the cause.

3. Failing fuse terminal:

 Once the fuse terminal is making poor contact, it could cause the fuse to heat up and blow. See what happens here, the fuse takes longer than a few seconds to blow and the current drawn by the bulb is reasonable. When this occurs,  then overheating is the likely cause.

4. A hot environment:

An environment around the fuse that may be too hot, when combined with the overheating of the fuse due to the current drawn by the headlight may be enough to blow the fuse. 

How do you stop a fuse from blowing?

Stopping a fuse from blowing is not tricky nor does it require a professional maintenance routine. Consider the following points if you want to stop your fuse from blowing:

• Use the right wattage of the bulb.
• Check the bulb for internal damage.
• Always check for shorts
• Inspect the pigtail’s internal parts to check for melting, burning, or any other damages. 
• Detect unusual signals by being observant
• Most especially, embark on a monthly maintenance routine to have your car checked.

Can a blown fuse cause the headlights to go out?

This is dicey as some blown fuse still allows for lighting. A blown fuse can as well cause headlights to go out in varying timing, some may take a few seconds and others right away depending on the case may be. You will be lucky if your blown fuse takes time to affect the headlights and cause them to go out when driving at night.

Another factor to consider is, depending on the cause of the fuse blowing which resultant effect will be a measure of time.

How to remedy a headlight fuse that keeps blowing 

Your headlight may keep going out for many reasons as discussed earlier, this may cause damage to your car as a blowing fuse signifies excessive power supply and passage of current through the fuse.

The following are steps to take if your fuse blows:

• Pop the headlight hood open
• Remove the battery connector
• Remove the clips of the plastic trims
• Unplug the pigtail wire
• Twist out the light bulb
• Install a new headlight 

Conclusion 

In order to stop your fuse from blowing, consider following the wire harness to the lamp. The short finder might help you. Additionally, you may look for a place where the wires may appear to be damaged or where they might be rubbing against metals and put it in order.

I believe this informative article will help you diagnose why your headlight fuse keeps blowing and how to fix the problem.