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On And Off-Road Lighting Tips And Tricks

Posted in How To: Electrical on May 1, 2012
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Nothing changes your perspective on nighttime wheeling or even just driving down paved roads like a good set of lights. And unless you’re driving a brand new $50,000 4x4, your factory lights suck in comparison to what is available. There are multiple ways to put more light in front of your 4x4, including off-road lights and headlight upgrade kits. But these can range from $40 to over $500, so it pays to know a little bit about the technology before whipping out the platinum credit card.

The Basics
In most vehicle lights, electricity flows through a thin piece of metal called a filament just like the soon-to-be-outlawed (in some areas) incandescent light bulbs in your house. The metal heats up almost to the point of melting, and the resulting glow puts the light in your lights. The reflector in the housing focuses the light in one direction, making it more intense. Headlights are rated in watts, and the most basic way to get a brighter light is install higher watt bulbs. These have larger filaments and sometimes different types of metal that handles higher amperage without melting. However, the filament is held in a gas chamber, and the type of gas affects the light output. Really old sealed beams were incandescent, and they use an inert gas. These lights give off a very warm, yellow glow. The filament starts to decay from the first time it is used, becoming dimmer and dimmer until they finally give up. The two most common gases used today for automotive headlights are halogen and xenon. Halogens produce a primarily white light, and the halogen gas causes a chemical reaction that redeposits separated parts of the filament back on the metal when the light is turned off, extending the life and maintaining the brightness of these lights over their life. Xenon is another gas that can be used in lights that have filaments, producing either a pure white or a blue tint. The color is caused by a different temperature at which the filament glows. Both halogen and xenon bulbs produce brighter light with longer life. To add some confusion, xenon is also often used to describe High Intensity Discharge (HID) lights.

Headlights have come in several forms over the past 80 years or so. The older styles were sealed beams (left) with the filament mounted in a large glass assembly filled with an inert gas. Over the past few decades, new vehicles transitioned to composite headlamps which use a plastic lens and reflector along with a replaceable bulb (right). These still use a filament, but the gas-filled chamber was reduced to the small area around the filament. The latest headlight technology is HID (center), which uses two tungsten electrodes and the light comes in the form of an arc between the electrodes.
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HID Lights
These lights have been used for decades by pro off-road racers for ultra-bright systems that operate at a moderate amp draw and lower temperature. An HID light doesn’t use a filament at all. Instead of heating a filament to the point of glowing, an HID uses electrodes that do not touch. When the gas in the tube heats up to the point of evaporation, an arc of light connects the electrodes. They use xenon gas in the tube, but don’t confuse a xenon light bulb with an HID. In addition to special bulbs – which some companies call a burner to distinguish them from filament-type bulbs – these systems also require a transformer to increase the voltage and create the arc, as well as a starter which literally starts the arc. While a halogen or xenon light attains its full brightness as soon as you turn it on, an HID has a warm-up period. A knock against HID lights has been the expense, but there have been several affordable off-road lights and headlight conversion kits introduced in the past few years.

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LED Lights
A relatively new technology for forward-facing lights is Light Emitting Diodes (LED). They’ve been popular for trailer and Jeep taillights for a long time, but the concept of using them for headlights or off-road lights is pretty new. In an LED, diodes are mounted on a circuit board, and are electrically charged to create light. They are extremely efficient, producing bright, white light with very low amperage draw. They are the fastest to light, and they also produce practically zero heat. A big advantage for off-roading is that they are nearly impervious to damage from shock and vibration.

We have to admit that when we saw the first LED replacement headlights a few years ago, we questioned the validity of the concept. But after trying them, we’ll attest to their brightness, coolness, and ruggedness. Truck-Lite offers 7-inch round LED assemblies that replace headlights. These use 10 LEDs in a single housing. Pro Comp and Vision X Lighting make a variety of off-road LED lights.
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Starting Point
When you’re ready to add more light, the best place to start is your headlights. You use these every day, um, we mean every night, so a step up here will be something you’ll get the most use and satisfaction from. Older headlights are a sealed beam-type; when the bulb goes out you replace the entire headlight. Newer systems are a composite made up of a plastic housing that has the reflector and lens and a replaceable bulb. For either of these types, you can upgrade to halogen or xenon bulbs with higher wattage ratings. You’ll probably want to stick with DOT-compliant bulbs to keep out of trouble with your local law enforcement and other motorists, but that’s up to you. There are plenty of legal choices as well as few off-road only options. As a safety precaution, some late-model vehicle electrical systems, such as that in the ’07-up Jeep Wrangler, sense the amp draw through the factory headlight switch and will shut-down the system if the draw is too high. If you want to go brighter than 60/55-watt bulbs, you’ll need to use a relay kit such as the one from Painless Performance shown in “To Relay or Not To Relay.”

There are even more choices when you dive into off-road lights. These don’t have to be street legal, so they can be much brighter and reach much farther. Pick a light that will produce the type of beam pattern you want as well as fit your vehicle and your budget. You can choose a traditional bulb like the Pro Comp 9-inch H11 light (top left) and Lightforce 170 Striker, or an HID such as this 7-incher shown from Rugged Ridge (right). All three of these companies offer high-output traditional lights as well as HID lights.

Beam Guide
The various types of light beams can be confusing, but they are really easy to understand when you see them together. The views in the accompanying graphic give you a birds-eye view of what each beam looks like on the ground. Standard headlights have a unique beam to illuminate the foreground well and then angle off to the right at a distance to minimize glare to oncoming traffic. The rest of the beams are symmetrical in their pattern.

More Brighter
You’ll probably want something better than street-legal headlights for beating through the bushes. This is where your options really open up. What size, how bright, where to mount, how many, and so on. One of the most common off-road light patterns is a driving beam. These lights are designed to essentially be long-range headlights, with a pattern that is 3 to 4 times as wide as they are high. A spot beam is round, and may also be called a pencil beam. These generally reach farther but aren’t always as useful for driving as they are for finding something in the distance. If you use these for off-roading, you’ll want a high-quality headlight high-beam to fill in the middle distance well. All of the same bulb technology, including HIDs, applies to dedicated off-road lights making it easy to find something that fits your needs, your budget, and your rig.

The Lightforce Stryker 170 is just under 7 inches in diameter and comes with a 100-watt Xenophot bulb. These lights are known for extremely good durability in a lightweight all-plastic design which means no rust. One cool Lightforce feature is an optional lens that converts a long-distance spot beam into a wide pattern or a combo. You can also convert these to HID later with a Lightforce conversion kit.

This is the light pattern of the original headlights in a ’09 Jeep Wrangler. Pretty marginal, but this is also very typical of a stock headlight system unless you have a high-dollar rig with factory HID lights.

Here is the beam of the IPF 60/55-watt upgrade bulbs. The light is much brighter, and it is also crisper and has a pure white color. Not only does it reach farther, but it also fills in the foreground much better than the factory lights

Adding the factory fog lights to the IPF headlight fills in the section immediately in front of the vehicle.

We then added the Lightforce Stryker 170 spot off-road lights which illuminated the trees 1,000 feet away quite well. These lights pack a lot of power: these as well as the HIDs shown in the next photo will reach farther than 1,000 feet.

This shot shows the Rugged Ridge HID off-road. One big difference with the Rugged Ridge HID light is that the light was less focused, providing better light over the entire area. Lightforce offers a diffuser filter for its lights which provides a similar effect.

To Relay or Not To Relay
Most off-road lights have high amperage consumption which means a lot of power and running through the wiring. If the company you get the lights from recommends using a wiring harness with a relay, use it. In fact, companies are a lot more likely to help you out if there’s a problem later if you use their wiring kit with their lights. A relay allows you to isolate the high-amperage wires, keep them short, and avoid routing them through a switch in the cab. In this arrangement, the switch you flick to turn on the lights actuates the relay, routing high-amperage power directly from the battery through the relay and to the lights.

You may want to consider adding a relay kit if you upgrade the headlights to higher wattage bulbs. If you jump from 35-watt to 60-watt lights, there’s a significant amperage increase which can overheat a headlight switch or the factory wiring. Painless Performance makes kits for two- and four-headlight vehicles that use the factory headlight plug for activation, and all of the high-amperage power goes through the Painless wiring and relays. In addition to being safer, this will also give you brighter headlights because there is less resistance in the system compared to using the factory harness.

Types of lights that generally don’t require a relay are LEDs and most HID systems. These consume low amperage so the factory wiring and switches are not overworked.


Rugged Ridge
Pro Comp
Compton, CA 90220
Falconer, NY 14733
LightForce Performance Lighting
Corona, CA 92879
Renton, WA 98057
Vision X Lighting

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