Upgrading the headlights on a 2016-2021 Toyota Tacoma is one of the most rewarding modifications you can do, and few products deliver a cleaner factory-plus look than a set of AlphaRex projectors. We put this AlphaRex Tacoma projector headlights installation to the test in our shop, following the process from the very first battery disconnect all the way to the final beam aim against the wall. In this guide we will walk you through every step we performed, share the wiring details for the daytime running light harness, and point out the little extras (like factory fender flares) that can change your removal process. If you have ever hesitated to tackle a headlight swap yourself, this walkthrough should give you the confidence to get it done in an afternoon.

Why We Chose AlphaRex for the Tacoma

The folks at AlphaRex specialize in designing and producing superior and uniquely stylish aftermarket automotive performance lighting with innovative technology, and the Tacoma lineup is a perfect example. When you are shopping for a set, you will typically see the NOVA-Series LED Projector Headlights and the LUXX-Series LED Crystal Headlights as the two main styling directions. In this article we are focusing on the projector installation, which follows the same removal and wiring procedure regardless of which trim of housing you end up choosing. If you want to compare price and availability across trusted retailers, we sourced our kit through the LED Projector Headlight Kit listing, and you can also grab a similar Front LED Headlight Upgrade Kit bundle depending on what accessories you want to pair with it. Both are reputable options that ship complete with the hardware you need for this job.

Tools and Prep Before You Begin

Before diving in, gather a basic set of hand tools. You will primarily need a 10 millimeter socket, a plastic trim pry tool, and a set of connectors for the wiring taps. AlphaRex recommends preparing your tools ahead of time so you are not stopping mid-job to hunt for something. Whenever you work on your vehicle, the very first move is a safety move. We always start by disconnecting the negative battery terminal. This protects the electronics and, more importantly, protects you while you are handling connectors and running new wiring near the firewall. Do not skip this step.

Step-by-Step AlphaRex Tacoma Projector Headlights Installation

Step 1: Disconnect the Battery

With your tools staged, disconnect the negative battery terminal. This is the foundation of the entire safe install, and it is the same rule we apply to every lighting project we tackle. Once the terminal is off and set aside where it cannot accidentally reconnect, you are clear to move to the grille.

Step 2: Remove the Grille

Start at the top of the grille by removing the two 10 millimeter bolts. After those are out, find the plastic mounting clip located at the upper corner of each headlight and pop it free. Next, unplug the connector to the sensor and release the two clips that hold that connector to the grille. With everything disconnected, carefully pull the grille out of the truck and set it aside. You will reinstall this later, so keep the bolts and clips organized.

Once the grille is off, remove the two plastic shrouds located inside of both headlights. These come out easily and give you better access to the surrounding hardware.

Step 3: Handle the Factory Fender Flares (If Equipped)

Here is where trucks differ. If your Tacoma is equipped with factory fender flares, you have a couple of extra steps before the bumper cover will come free. Remove the 10 millimeter bolt that attaches the front fender flares to the bumper cover on both sides of the vehicle. Then remove the plastic clips holding both inner fender liners to the front bumper cover, and carefully pry the fender flares free from the bumper covers.

Take your time prying the flares off. The plastic clips can be brittle, especially on older trucks, so working slowly here saves you from cracking anything. If your Tacoma does not have factory flares, you can skip straight ahead to the bumper cover clips.

Step 4: Loosen the Bumper Cover

Now remove the four plastic clips attaching the bumper cover to the front of the vehicle, plus the two plastic clips located near the bottom corner of each headlight. With all of those released, carefully pull the bumper cover forward, just enough to expose the bolts that hold the headlights to the vehicle. You do not need to fully remove the bumper cover, only free it enough to reach the headlight hardware.

Step 5: Remove the Factory Headlight

With the bumper cover pulled forward, you can now see the four bolts holding the headlight in place. Remove all four bolts, then lift the headlight out of the vehicle. As you pull it free, unplug the four connectors on the back of the housing. That fully separates the factory headlight from the truck and clears the way for your AlphaRex unit.

Step 6: Wire the Daytime Running Light Harness

This is the part that trips up most first-timers, so we slowed down and documented it carefully. Connect the daytime running light harness with the red wire to the battery positive and the black wire to the negative, using the 10 millimeter bolts on the firewall as your grounding and power points. In order for the daytime running light to function during the day, you will need to tap the gray wire into your IJ or EFI number three fuse (10A). Once that tap is made, route and connect the two red wires, running one to the back of each headlight. This is what tells the DRL circuit to activate when the truck is running.

Step 7: Connect and Secure the New Headlight

With the DRL harness set, connect the turn signal, low beam, high beam, daytime running light, and turn signal wiring harnesses to the AlphaRex headlight. Then finish the installation by securing the headlight to the truck with the four bolts you removed earlier. Snug them evenly so the housing sits flush.

Repeat the previous steps for the opposite side headlight, following the same removal and installation sequence. When both sides are in, follow the previous instructions in reverse to reinstall your factory bumper cover, fender flares, and grille. Take your time reseating all of those plastic clips so nothing rattles down the road.

Step 8: Test and Aim the Headlights

Before you consider the job finished, reconnect the battery and test the functions of your AlphaRex headlights to make sure everything works properly. Cycle through the low beams, high beams, turn signals, and daytime running lights. If a function does not respond, double-check the corresponding connector and your DRL wire taps. Once everything checks out, it is time to aim the beams. Park the vehicle 25 feet from a wall and level the headlight beams evenly. Turn the adjuster clockwise to lower the light or counterclockwise to raise it. Getting both sides matched keeps you legal and, more importantly, keeps you from blinding oncoming drivers while giving you the best possible spread on the road.

Our Takeaways From the Install

Overall, this is a very approachable install for anyone comfortable with basic hand tools. The only real complexity is the DRL harness wiring, and once you understand that the red goes to positive, black goes to negative, and gray taps into the EFI number three 10A fuse, the rest is straightforward. The factory fender flare step is easy to overlook, so if your truck has them, plan for those extra bolts and clips up front. When you are done, you get a modern, aggressive front-end look with the improved night driving that AlphaRex is known for. If you want to see how a different style of headlight goes in on the same platform, we also recommend reading our Tacoma Lensless LED Headlight Install Guide for another perspective on upgrading your Tacoma lighting.

Frequently Asked Questions

What is the first safety step before installing AlphaRex Tacoma headlights?

Disconnect the negative battery terminal before beginning any work on the vehicle.

How do you remove the grille to access the headlights?

Remove the two 10 millimeter bolts on top of the grille, then the plastic mounting clip at the upper corner of each headlight, unplug the sensor connector, release the two clips holding the connector to the grille, and pull the grille out.

What extra steps are needed if the truck has factory fender flares?

Remove the 10 millimeter bolt attaching the front fender flares to the bumper cover on both sides, then remove the plastic clips holding the inner fender liners before prying the fender flares free.

How is the daytime running light (DRL) harness wired in?

Connect the red wire to the battery positive and the black wire to the negative via the 10 millimeter bolts on the firewall, then tap the gray wire into the IJ or EFI number three 10A fuse and route the red wires to the back of each headlight.

How do you aim the new AlphaRex headlights after installation?

Park the vehicle 25 feet from a wall and turn the adjuster clockwise to lower the beam or counterclockwise to raise it, leveling both headlights evenly.