Step 1: Remove stock headlights
Remove the corner lights (also referred to as marker lights) and the filler panels below the headlights (if necessary). Then, unplug and unbolt the stock headlights.
Step 2: Install the projector wiring harness
The projector wiring harness is the biggest wiring harness. On the driver side it has one red terminal connector and one black terminal connector. Connect these to the battery. On the passenger side, connect the negative (black) terminal connector to the fender bolts to ground it. Make sure there is no rust, paint, or corrosion that can prevent that side from being grounded. Connect the three prong H4 connector to the stock H4 plug that was originally plugged into the stock lights. There is only one of these plugs on the harness.
Step 3: Install the Halo Drivers
Switchback halos (white and amber) have three wire colors on each driver: red, yellow, and black. Red is power for white, yellow is power for amber, and the black is ground. There are multiple ways to install these — you can tap the red wire into the marker lights or tap into the accessory fuse inside the truck. The yellow wire needs to be tapped into the turn signal positive wire, and the black wire can be grounded on the fenders with the other grounds.
Step 4: Install the headlights
Connect all the wiring harness plugs into their matching plugs that are coming from the back of the headlight. Replace the 10mm bolts that were holding the headlights in originally as well as the corner lights and filler panels, if you had to remove them. Turn on the vehicle and test the lights! Make sure the halos turn on (if you ordered them), make sure the low beams are on, and flick the high beams on and off to make sure they’re working correctly as well. If anything isn’t working as it should, check to make sure all of the plugs are securely connected and check your grounds.
Step 5: Aim the headlights
Click THIS VIDEO to learn how to correctly aim your headlights. These headlights are VERY bright, and it is paramount that they are aimed correctly so you aren’t giving other drivers any unwanted x-rays.