Installing an adjustable headlamp on your vehicle can improve your ability to see the ground (while driving off-road) or your visibility in low light conditions. It is important to note that the use of a directional headlamp on public streets is illegal in many areas, so check the laws in your region before installing it so that you can use it while driving. Although some directional headlamps can be installed without the use of a relay, this method is still recommended for optimal performance.
Part 1 of 3: Plan the mounting locations
Step 1. Disconnect the battery
Before working on your vehicle's electronics, it's important to disconnect the battery to avoid electrocuting yourself or causing damage. Open the hood and use a hand wrench or socket wrench to loosen the nut that holds the black ground wire over the negative battery terminal. Once loosened, you should remove the cable and place it on the side of the battery to prevent it from coming into contact with the terminal again.
- You can locate the negative terminal by looking for the letters "NEG" or the negative symbol (-) on the battery.
- You don't need to disconnect the positive cable.
Step 2. Choose a suitable mounting location
There are several places where you could feasibly mount a steerable headlamp, so choose the location that works best for your purposes. Some common locations include the top of the side mirror or the roof of the vehicle.
- You will need to first identify the location where you want to mount the headlight to cut the proper lengths of wire.
- Remember that if you decide to install the headlight on the roof, you will have to drill a hole in it, which can lead to leaks.
Step 3. Determine the type of light you are going to use
There are several options on the market for directional headlights and their installation kits. The three common types of headlights you can buy are halogen, LED, and HID. Each style of light presents its own strengths and weaknesses, and you should choose it based on your application and budget.
- Halogen lights are the cheapest and are usually the dimmest. However, the bulbs are less expensive to replace when they burn out.
- LED lights can be extremely bright and cost more than most halogen headlight applications.
- HID headlights are the most expensive, but they offer the longest life and are often the brightest.
Step 4. Determine where you want to place the switch
You can install a button or a switch inside the vehicle to turn the headlight on and off. In many headlights, the switch sits above the light itself and does not require further wiring. However, the installation will be a bit more complicated if you choose to connect the light to a switch on the instrument panel. If you decide to install a switch over the light itself, you should leave it in the "on" position.
- Even if the light has a switch, you can still choose to flip the switch through your vehicle.
- You must determine where you want to locate the switch to determine how much cable you will need for this project.
Part 2 of 3: Wiring the Directional Headlamp with a Relay
Step 1. Mount the relay in the engine compartment
If your headlight does not come with an electrical relay, you will need to install one. Most directional headlamps should not be connected directly to a power source without going through a relay. If your kit doesn't come with one, you should purchase a SPST (Single Pole One Direction) relay from a local auto parts store. Mount it inside the engine compartment somewhere on the bodywork.
- Try to avoid mounting the relay too close to the exhaust manifold, as heat can damage it.
- You can use heavy-duty double-sided tape or adhesive, or pierce through the metal to mount the relay.
Step 2. Connect the relay to ground
Run a short length of black wire from the relay to a bolt on the bodywork or frame of the vehicle. Expose a length of wire to one end and loop it. Then loosen the bolt and wrap the exposed wire under the head. Twist the cable on itself to secure it to the bolt, and then tighten the bolt again.
- This wire will provide the ground for the relay circuit.
- Whenever possible, you should use black wires for grounding and for easy identification.
Step 3. Run a wire from the relay to an in-line fuse
Purchase a fuse holder online and connect it to the positive post of the relay. You may have to run the wire from the positive post to the inline fuse holder if you can't connect it directly. Make sure there is a fuse in the fuse holder rated to handle the amperage required to power the headlight.
- This fuse will protect the headlight and relay from overvoltages if there is a problem with the electrical system.
- The fuse will blow if too much power flows through it, cutting off the power and preventing a fire.
Step 4. Connect the fuse to the positive battery terminal
Run a length of wire from the fuse holder to the positive battery terminal. You can choose to wrap a length of exposed wire around a bolt in the battery wire, or buy a new end of positive wire. If you do, you should insert the end of the positive wire and the fuse wire from the relay into the end. Then, use pliers to compress the end of the wire until the wires are held firmly in place.
- This wire will supply the power to the relay and then to the headlight itself.
- Make sure the wire is securely attached to the positive terminal. If it is released, the headlight will not work.
Step 5. Connect the relay to the positive post on the headlamp
Run a wire from the relay to the positive post on the headlamp itself. You can choose to twist the wire around the positive post or solder it in place. Regardless of how you connect the wiring, be sure to wrap it in electrical tape or a shrink sleeve to protect the connection from the elements.
Soldering is the strongest and most permanent way to connect the wiring to the headlight
Step 6. Run a wire from the relay to the switch
Run a wire from the last open post over the relay to the switch in the vehicle if you decide to mount one. This procedure will allow the switch to cut off power to the headlamp. You may be able to thread the cable through a hole in your vehicle's fire wall on the driver's side. This will bring the cable out near the pedals inside the cab.
- If you can't run the cable through the fire wall, insert it into the corner where the hood, fender, and driver's side door meet.
- Be careful not to run the cable through anything that can melt or break with regular use of the vehicle.
Part 3 of 3: Assemble the Wired Components
Step 1. Drill mounting holes for the headlight
Use the tool provided with the swivel headlight kit to mount the light in the chosen location. If your headlamp is designed to be ceiling mounted, it will likely come with a strip of weather resistant material to prevent water from seeping through the ceiling where you will drill the holes. Otherwise, you can apply silicone in and around the holes while screwing the light into place to create a waterproof seal.
- If you choose to mount the light over the mirror, it will not be necessary to use a weather protection.
- Mounting a headlamp on a light bar or attached bracket also does not require drilling or weather protection.
Step 2. Install the switch on the instrument panel
Secure the switch on the instrument panel in place by making a hole in the trim and sliding the switch from behind. This way, only the switch will be visible and the rest will be located behind the edge. Place the screw on the cover above the switch, with the switch sticking out through it. Then screw it into place to hold the switch against the trim.
- If you decide to use a button instead of a switch, you must install it in the same way.
- Make sure the switch is easily accessible so you don't have to use the light while driving.
Step 3. Connect the switch to ground
Run a black wire from one of the three prongs above the switch to a bolt in the bodywork or frame of the vehicle just as you connect the relay under the hood. Make a loop with the exposed end of the wire and wrap it around a bolt. Tighten the bolt in place once the procedure is complete.
The switch needs its own ground and power supply to function properly
Step 4. Run a wire from the switch to a switching power supply
Locate the fuse box on the driver's side of the cab of your vehicle. Identify a fuse that powers an electronic device that only works when the vehicle is on (for example, the radio, headlights, or flashers). Remove the fuse and insert and "add a circuit" or the standard blade fuse holder with a dangling flexible wire so you can connect the wire from the switch. This will prevent the headlight from working when the vehicle is not on.
- Make sure you put a fuse in the fuse holder to turn the switch on.
- Review the instructions for the headlight and be sure to use a fuse rated for the amperage necessary for the light to work.
Step 5. Insert and secure the wiring
Once you have connected everything, reconnect the battery and insert the wiring so that it is not visible. Use zip ties under the instrument panel to secure any extra cables underneath it and prevent you from accidentally touching it with your feet or the pedal. Run any wiring on the outside of your vehicle along the edges until you can insert it under or between the body panels and prevent it from being visible.
- Reconnect the battery and test the new headlight.
- If the light doesn't come on, make sure none of the wires have been crimped or disconnected from their terminals to interrupt the flow of electricity.