Everything You Should Know About Light Bars

Seen any modified trucks in the last five years? You probably have, and odds are every single one of those trucks had some type of aftermarket light bar on the front. But before you run out and buy one, here's a look at everything you should know about light bar mounting, wiring, and expected life.

Source | Brett Levin/Flickr

Why the Light Bar Trend?

Off-road rigs have needed upgraded, better-than-factory lighting since the first Ford Model A truck went down a muddy unlit road. The original customizers solved their problem by adding more factory headlights to get the light output they needed, until the aftermarket stepped up and offered better halogen lights. Marty McFly's lifted Toyota SR5 in Back to the Future featured a rack of KC HiLiTES behind the cab. They looked cool, but also offered real-world practicality, far exceeding the era's 55W halogen headlight output. While the light output was better, the bulbs still needed replacing often, and the power draw could make the install complicated.

LED light bars deliver bright light at a low power cost and with huge reliability and lower operating temps. Enthusiasts knew this for years, but LEDs were too expensive for aftermarket use until recently, when economy of scale kicked in and prices dropped (have you checked the price of household LED bulbs lately?). If you wanted to replace your vehicle's interior bulbs with LEDs in 2005, you could easily have dropped hundreds of dollars. LED costs have fallen dramatically in the last decade, and now interior replacement LEDs can be had for just a few bucks, with are a huge variety of options.

Today's off-road lighting solution is the LED light bar. The light bar increases reliability by using long-life LEDs over delicate incandescent or sealed-beam bulbs. The LEDs are shielded in the case by rubber isolators that reduce vibrations, further improving component life. LEDs are also brighter than incandescent bulbs of the same price, offering a larger field of view at night, and farther reach. The light bar offers simpler and easier installation over multiple off-road lights, as you aren't limited to just mounting on a headache rack.

What to Consider Before Buying a Light Bar

Before you hit the “buy now" button, consider what you need from a light bar. What is your goal? Do you want to go off-roading, camping, hunting, or do any other activities that extend into the dark hours?

If so, light bars will provide additional visibility at night, and your main consideration should be to compare the light output in lumens from one bar to another to determine how far they reach. Get the highest lumen bar that fits your budget.Are you just looking for something cool for your show truck? That's great, too—you'll want to primarily consider packaging size and style. A "murdered-out" Wrangler doesn't need a chrome bar housing, but a matte or wrinkle-coated finish would look sweet. Also, plan where you will want to mount it—that will determine the size you need. Mounting locations up front can be in the grille, mounted to the front bumper, brush guard, or even the roof of the cab. For a show truck, also make sure it's possible to hide the wiring for a flush look

If you're considering these for a work vehicle, for use at night on a ranch, or out in an oil field, you have a few different needs. Look for a waterproof housing that can protect the internal parts from the heavy-duty work and weather that you're throwing at it. Then look at the other options available.

Light Bar Options

  • Size – Some light bars are 4 feet wide and can be mounted anywhere, while others are 5 feet wide and meant to be mounted on the roof. No, it's not just about finding the biggest bar. Get the size that fits the truck.
  • Colors – In addition to different sizes, you can get lights that change colors. Blasting more than just white light is cool at shows but could also serve a real purpose at a job site—or example, blue lights when the bed is empty, green lights when fully loaded.
  • Bluetooth – If a traditional switch isn't your thing, some companies produce a smartphone app that lets you control the light bar through Bluetooth. This is a neat feature when you're outside your truck and need to turn the lights on or off.
  • Install kits – Check the light bar that you're interested in to see what it comes with. Some are just the light bar itself, while others offer a kit with mounting brackets, nuts, bolts, relay, a switch, and wiring.

Light Bar Installation

Installing a light bar on your truck only requires basic tools. We're talking a good socket and ratchet set, extension, and probably a hex key (Allen wrench) set. If you didn't receive a kit and are piecing together the wiring, you'll also want a multimeter and wire cutter/crimper. A drill is useful if you're making your own mount in a bumper but is not needed if using the available attachment holes in a brush guard. Most light bars don't come with instructions, so here's a few tips:

  • Unravel the wiring harness and lay it in the engine bay, approximating how you want the wiring to go. This helps identify where each wire connects, routes on hiding the wiring out of sight, and options to run through the firewall. Usually this is through a grommet on the driver's side, but it can vary by the vehicle.
  • Soft-mount the light bar in place and see how it looks. You can use double sided tape to secure it in place before drilling any holes. Make sure the location works aesthetically and for aiming the light beam. Double check that it is centered before drilling mounting holes.
  • Then it's just a matter of bolting down and connecting. Measure twice and drill once, and tighten bolts to recommended specs. Connect the positive and negative wiring connections to the light bar, then run wiring through the firewall and connect the terminal to the on/off switch. Then connect the positive wire to the battery and find a solid ground for the negative wire. The relay can use any ground bolt in the engine bay that is convenient and away from heat. Rather than using just the factory switch, it is possible to activate a light bar with your high beams. This will require setting up a relay that taps into the high beam trigger wire from the multifunction switch. Consult the wiring diagram in your repair manual for specifics.
  • Test the light bar at night in an empty parking lot or field, and aim it to maximize light output distance.

Ever installed a light bar? Let us know your insider tips in the comments below.

Last updated March 6, 2023