For those wondering how to test a motorcycle headlight, this is the easy way to do it. It’s not just something you should be doing if your motorcycle headlight isn’t working, to test if the headlight is broken. This is also a great thing to do BEFORE you start installing a motorcycle headlight, and it’s super easy to do!
How to power a headlight directly from a motorcycle battery – all you need is:
- A motorcycle headlight (duh)
- A motorcycle battery (if you have any motorcycle made in the last 30 years, you probably have one!)
- Some wire with some conductive properties (commonly found on the floor of your garage behind your tool box, or here)
Since my battery was dead, I also used a Ctek battery charger to power things – I like the ones with a motorcycle mode and a car mode.
There isn’t much to explain, but despite it being simple, there isn’t a lot on this procedure on the internet that applied to motorcycling as a whole, so we’re gonna change that!
Essentially the goal is to get the negative terminal of the motorcycle battery connected to the ground wire of your headlight. You know what? I’ll just make you a picture:
Pretty self-explanatory, right? One wire from the negative battery terminal to the headlight’s ground (usually black) wire. One wire from the positive battery terminal to the contact for the headlight (test the high beam and low beam terminals individually).
How to test a motorcycle headlight video
Some people hate reading. I get it. Fear not, I’ve got you sloths covered!
Click the little unmute button in the bottom left corner to unmute the video.
1: You’ll wanna use the proper nut and bolt that came with your battery for a tight and strong connection/contact on the battery terminal.
2: If your battery is dead this won’t work. My battery was dead. I kept mine on a battery charger and that worked.
3: Let’s be real. I’m a motorcyclist, not an electrician. The only thing I know about AC and DC involves a full grown man with a guitar dressing up in a school boy outfit. I’ve probably butchered the name of every single electrical component listed on this page. Whatever, who cares.
Overall, if you have even an ounce of common sense and you aren’t thinking of trying this from inside a swimming pool, it’s an easy way to make sure your headlight is working. It’s a great way to troubleshoot your motorcycle’s headlight wiring harness too. For example:
- Headlight works when hooked up to the battery but not when hooked up to your motorcycle? You’ve got a wiring harness issue.
- Headlight doesn’t work when hooked up to the battery, or when hooked up to your motorcycle? Headlight is no good.
- Headlight doesn’t work when hooked up to the battery, but does work when hooked up to the motorcycle? You’re just plain doing it wrong.
How did we even get here?
Well, last week I tried to install a new Daymaker style LED headlight on my Harley-Davidson V-Rod, and that kinda failed (see for yourself). Testing the headlight was part of how I fixed the problem this week.
The part where I beg you for your comments
*Ahem* If you have any questions or comments, please leave them in the comments section below! Things you can comment about:
- If this helped you learn how to test a motorcycle headlight
- If I used the wrong words/terminology or made a typo somewhere (Hello, Michael Scott!)
- If this didn’t help you and now you burned your house down
Overall leaving a comment just helps me to know that I’m not just out here talking to myself, so feel free to say hi!