Tech Talk: Motorcycle Lighting Part 2 – AUX Lights

In this write-up, I will show you how to install a set of LED AUX lights on your bike. You can read the other write-ups here:

Choosing the Right Lights

As far as lights go, we can distinguish 2 main types of lights:

  • Driving lights: Also called headlights, these lights are used at night or during low-light conditions. The beam is of medium length and fairly narrow, in order not to blind oncoming traffic.
  • Auxiliary lights: Also called AUX lights, these are lights that are not certified for headlight use. Instead, they are designed for specific purposes.

The most common types of AUX lights are:

  • Fog lights: Designed to increase visibility in bad weather (i.e. rain or fog). The beam is wide, short and low, illuminating the area directly in front of the vehicle.
  • Flood lights: Designed to illuminate a much broader area than that of your driving lights. The beam is scattered, litteraly flooding the area with light. Since focus is low, the light intensity is fairly low, too.
  • Spot lights: Designed to have a very long range and a narrow field of view. The beam is focused and, therefore, has high light intensity. They are usually not road legal, as they easily blind oncoming traffic.
Courtesy of

LED AUX lights come in all kinds of sizes, shapes and power outputs. There is cheap unbranded crap, as there is overpriced branded stuff. Do your homework and figure out exactly what you need and how much you’re willing to spend.

Despite what I wrote, I decided to go with spot lights. There’s a fine line between what’s legal and not-so-legal in Vietnam. Clearly, no one will pull me over for having spot lights. Case in point, Vietnamese drivers usually drive with the high beams or fogs on for no apparent reason. I get blinded by oncoming traffic all the time. With a pair of spot lights, I can return them the favor.


For this upgrade, I sourced the following parts:

  • Spot Lights: Obviously without lights, I wouldn’t be writing this post… I went for a pair of Gold Runway X4 spot lights – “4” referring to the number of CREE LEDs. Each light has 4 powerful 10W CREE LEDs. You can also find 50 and 70 Watt variants, but these would easily overload my bike’s electrical system. Check your bike’s alternator specs before pulling the trigger.
  • Wiring Harness: This one is optional, and depends on (1) your electrical skills and (2) your willingness to hack into the stock wiring (hopefully for your bike, there’s a strong correlation between these two conditions). I bought a full wiring harness, including a switch, fuse, relay, 2 waterproof connectors and a control unit (flash control).
  • Mounting Brackets: Optional. Depending on how abundant your skills and time are, you can fabricate a pair of brackets. I figured it would be more time and cost-effective to buy brackets (probably a lot safer too….).


Depending on the motorcycle, installing AUX lights can be daunting. Usually, it involves removing part of, if not all, the fairings. I recommend keeping a repair manual within a hand’s reach, just in case. Japanese bikes are usually less complicated than their European counterparts, and the Versys-X is no different. I only had to remove the seat and one side panel. It might be a different story on your 1250GS…

Wiring AUX lights isn’t rocket science. You can either splice the stock harness and wire the lights in, and operate them with the standard switchgear, or add a separate harness, switch and relay. The lazy bastard that I am, I bought a complete harness.

You want to make sure your wiring is reliable and waterproof. So here are some quick tips :
– Use appropriate tools (e.g. crimp tools for the wiring)
– Use good quality consumables (e.g. electrical tape & wires, shrink sleeves, …)
– Route the wires away from hot spots (e.g. the engine), sharp edges and areas exposed to water

The wiring harness was too long for the Versys-X. I ziptied and tucked it away behind the side panel. Then I secured the control unit with double-sided 3M tape.

Underneath the seat, I wired the harness as follows: positive and negative wires (no. 1 & 2) directly to the battery, “relay” wire (no. 3) to a switched power source in the fuse box. Last but not least, I made sure to put the fuse (no. 4) in a spot where I can easily reach it.

In my case, the relay is triggered by the ignition switch. As soon as, I turn the ignition on, the relay circuit will be hot. This is called “positive switching”. By doing this, the relay will not work unless the bikeโ€™s ignition key is turned on. This prevents me from accidentally leaving the lights on and draining the battery.

After running the wiring, it was time to install the switch. This proved to be tricky, because the Barkbusters handguards brackets occupy strategic real estate on the handlebars… I really wanted to fit the switch that came with the wiring harness. However, I was only able to fit it on the right-hand side. After a quick test ride, I realized that operating the light switch with my right hand was like masturbating with my left hand. It just didn’t feel right… So, I ended up buying another switch.

With the wiring and switch in place, it’s time to install the lights. Each X4 light comes in at a hefty 550g. This is due to the large aluminum housing, which acts as a heatsink. As far as I can tell, the build quality is excellent, but only time will tell… Added bonus, the lights were plug and play with the harness, so I didn’t have to fiddle with the connectors.

It’s important to install the lights in a suitable location. Adventure bikes usually have crash bars, which gives you some flexibility.

With the brackets in place, the last step is installing the lights. Don’t start reassembling your bike yet, until you have actually tested the setup at night.

Final Setup

I bolted the spot lights underneath the fog lights. This setup works well as far as performance goes. The lights are extremely powerful, with a combined output of 80W!

However, I’m not entirely happy with the current setup. I feel the lights are quite exposed in case of a spill. Ideally, I would like to install them a bit lower, where they are protected by the crash bars. I’ll be updating this post, as I play with different setups. Trial & error.