Replacing a headlight in most cars is a pretty straightforward process and one you can usually do yourself without the help of a mechanic.
And you’ll know how much of a fan of LED headlights I am. If you don’t, check out my blog.
But there is one vital thing to think about when you install LED headlights, and that’s making sure you get them the right way round.
It is possible to install LED headlights upside down, but this will make them dangerous – as they might blind other drivers or have misaligned beams. Ensure the diodes are horizontal and the shield, if the bulb has one, is at the bottom.
In this article I’m going to explain to you:
- Why upside down headlights are dangerous
- How you can tell whether they’re upside down
- The proper orientation for the diodes on the bulb
Why Installing LED Headlights Upside Down Is Dangerous?
LEDs are low wattage, so the chances of hurting yourself when you install them are pretty much non-existent.
So as long as you plug them into the headlight, connect the power cable, and turn them on, they aren’t dangerous, right?
If you install headlights upside down, it could be hazardous for you and other drivers.
The main reason is that if you install them the wrong way up, you will entirely change the headlights’ beam pattern.
Low beams will actually be as bright as high beams. This can blind oncoming traffic, which could cause accidents.
According to a survey by the RAC in the UK, drivers claim that it can take them up to five seconds to recover if they’ve been blinded by headlights. If you’re traveling at 60mph, that means you’re blinded while driving 135 meters in five seconds – a lot can happen in that time.
In most US states, the law says that you can’t have your high beam headlights on within 500 feet of another vehicle – both oncoming or in the same direction, as you could dazzle someone in their mirror. To keep your vehicle road-legal, you need to make sure your headlights aren’t blindingly bright.
Even if you don’t end up accidentally blinding other drivers, you’ll just be able to tell that the beams aren’t right. They might point too low, directly in front of the car, or they could point further upwards, more into the sky than straight ahead.
Either way, you won’t get the proper visibility you need, which makes driving in darkness or poor conditions more dangerous if your LED headlights aren’t installed correctly.
The fact that LED lights are much brighter compared to halogen bulbs, puts even more pressure to ensure that they are installed correctly.
How Do I Know That My Headlights Are Upside Down?
If you think your headlights might have been installed upside down, there are some relatively simple checks you can do to find out. You can remove the bulb from the reflector, which I’ll go through below when I cover the correct orientation, or you can just do an aiming test.
To do this, you’ll need a wall that you can mark either with chalk or tape. The inside of your garage is perfect, as long as you have space to drive 25 feet away from it.
Start by driving close to the wall and using the chalk or tape to mark the spots on the wall that are level with the center of your headlights. Once this is done, draw or mark a line between these two spots. This isn’t essential, but it’ll make it easier to check your alignment.
Then, reverse so that you’re 25 feet from the wall, and switch on your low beam lights. You should be able to see on the wall where the center of the light is projected.
If the center of the beams matches the marks on the wall, your lights are installed correctly. If they’re out by a few inches, then you might just need to tweak the alignment.
Some vehicles let you do this automatically, while others will require manual tweaking of the fitting. Check your owner’s manual.
If the beams are pointing well below or above the line you’ve drawn, and I’m talking a couple of feet or more, then you likely have your bulbs installed upside down, and they will need to be re-installed.
If you don’t have access to a wall and don’t feel confident in removing the bulb yourself, take your car to a mechanic.
They can use a special beam setter tool to check the alignment, and rotate your bulbs for you if necessary. Of course for the additional cost.
Vertical Or Horizontal: What Is The Correct Orientation?
The other way to check that your headlights are installed the right way up is to remove the bulb.
So here I’ll tell you how simple it is to make sure they’re aligned correctly, whether you’re checking your existing bulbs or installing new ones.
Your headlights don’t simply project light forwards. Instead, it’s made up of angled mirrors that direct your beam forwards.
But if the light doesn’t hit those mirrors at the current angle, you’ll end up with a weaker beam, a beam that’s too strong, or one pointing in the wrong direction.
Some LED bulbs have two diodes on each side, with one slightly above the other. These are called dual-beam lights, and both low and high beam diodes are put onto the single LED bulb.
If that’s the case with your bulbs, the slightly higher diode should be on the upper-side of the bulb.
And one final check you can do – most LED bulbs have a shield (halogen bulbs have these also), which helps to make sure the light is correctly directed. This shield should be at the bottom of the bulb.
Most high-quality LEDs will have alignment lines that help you to install them correctly into the headlight housing.
Just in case you are like me and prefer an easy solution, I would suggest you check out the Last headlights.
If you’re still not clear, then check out this useful video I found. It’s a self-explanatory guide on how to check your bulbs are installed correctly and what can go wrong if they’re upside down.
It’s surprisingly easy to install your LED headlights the wrong way round if you’re not paying attention, but that’s why you must check them.
Your headlights should never be misaligned or too bright for your own safety and that of other drivers.
Have you made the switch to LEDs, and if so, how easy did you find it to swap the bulbs?
And have you ever used the wall test to check your headlight alignment?
Let me know in the comments, and I’ll be happy to help you if you want to know more.