Fits: 2018-2023 Ford Mustang S550 facelift — EcoBoost, GT, Bullitt, Mach 1 and Shelby. Works with all factory light sources.
This is the facelift car only. The 2015-2017 pre-facelift uses a different headlight and needs two adapter harnesses this one does not — see the 2015-2017 Mustang headlight guide.
These steps cover both builds, Clear and RGB. Removal and fitting are identical; the RGB build has an extra app setup section at the end.
This generation plugs straight into the factory harness — there is no adapter to hunt for in the box.
The front bumper has to come off. It is held from above, below and inside both wheel wells, with two hidden nuts per side, so give yourself time and keep the hardware sorted.
Before You Start
- Park on level ground, switch off, and disconnect the negative battery terminal while handling wiring.
- You will need to raise the car safely to reach the belly pan bolts.
- Use masking tape along the fender and hood edges so nothing gets scratched.
- Do not put dielectric or weather-sealing grease on connectors or sockets.
- Leave the bumper and belly pan off until every function has passed testing.
Required Tools
- Trim removal tool or panel clip tool
- Metric socket and ratchet set, including 10 mm and 13 mm
- Phillips and flat screwdrivers, or pliers for the push clips
- Jack and jack stands
- Masking tape and clean microfiber towels
- Zip ties
- A flat wall for beam aiming
Part 1: Remove the Front Bumper
Step 1: Remove the Upper Radiator Cover
Use a screwdriver or pliers to remove the eight plastic push clips, then lift the cover off.
Step 2: Remove the Upper Bumper Fasteners
Remove the six large bolts along the top of the bumper, plus one small screw on each side.
Step 3: Release the Belly Pan
Raise the car safely. Remove the six lower bolts and the push clips on both sides. Leave the belly pan attached to the bumper — it comes off with it.
Step 4: Release the Wheel Well Liners
Remove the wheel well clips and pull the liner back. Press the center of each inner retainer and remove it. Then use a 10 mm socket to remove the two hidden nuts securing the bumper to the fender.
Step 5: Disconnect and Remove the Bumper
Disconnect the parking light connector on each side. Lift the bumper off the five upper locating pins, then carefully pull it forward and away. Lay it on cardboard or a mat.
Part 2: Remove the Factory Headlights
Step 6: Unbolt and Unplug
Remove the three headlight bolts — 13 mm for the side bolt, 10 mm for the other two. Disconnect the main wiring connector and lift the headlight out. Keep the factory lamp on the bench as a reference until the new one is in.
Part 3: Install the New Headlights
Step 7: Connect and Mount
Connect the factory wiring harness straight to the new headlight and confirm the lock tab clicks home. Place the headlight in the factory position, reinstall the locating clip and the three mounting bolts, then repeat on the other side.
Before you fully tighten, nudge each lamp until its edges line up flush with the hood and fender — that is what gives you even body gaps. Zip-tie any slack so nothing can rub or pool water.
Step 8: Test Now, Before You Reassemble
Switch the lights on and run through low beam, high beam, DRL, parking light, left and right turn signals, hazards and the sequential sweep. Cycle the ignition twice and confirm no hyperflash or flicker. Catching a problem here saves taking the bumper off twice.
Step 9: Reassemble and Set the Beam Aim
Refit the bumper, belly pan, wheel well liners and upper radiator cover in reverse order, reconnecting the parking light connector on each side. Check no wire is stretched or pinched.
Then check the beam aim: park square to a flat wall about 25 feet away on level ground, mark the height of each beam centre, and use the adjusters to bring the cut-off line level and even across both sides. A projector aimed too high is worse for oncoming traffic than the lamp it replaced.
The Clear build is now fully installed. The next section applies only to the RGB build.
RGB: Star Light Running App Setup
1. Animation control. The app controls the daytime running light animations. The startup animation is preset and cannot be changed.
2. Download the app. Search for "Star Light Running" in the App Store or Google Play, or scan the QR code on the controller box.
3. Bluetooth connection. Open the app, tap Add Device (Figure 2), open the interface (Figure 3), and select the nearby device.
4. Adjusting modes.
- Dynamic mode: the number in the center of the blue box shows the current mode. Tap + or - to switch effects, or AUTO to cycle through all of them.
- Static color: drag the color wheel in the green box, or tap a preset color. This stops any running animation.
- Brightness: drag the slider in the first row of the red box.
- Speed: drag the slider in the last row of the red box.
Tip: if you used the older "Light Running" app and have trouble connecting, use "Star Light Running", the upgraded version.
Road use. Color modes are for show and display use where permitted. Confirm that the standard road-light functions work normally before using any color mode.
Common Issues and Solutions
One headlight does not turn on. Recheck the main connector lock and the corresponding fuse. Inspect the pins inside the connector; if any are bent, straighten them carefully and reconnect.
Swap test. If a headlight still does not work, swap the left and right units to find out whether the issue is the light or the car's wiring.
The parking light in the bumper does not work. Its connector was disconnected in Step 5 on each side. Confirm both went back on when the bumper was refitted.
Warning, flicker or hyperflash. Confirm the main connector is fully seated, and that any included decoder or relay is connected and secured.
The bumper will not sit flush. Check for a trapped harness, a broken or missing clip, one of the five upper locating pins not engaged, or a hidden fender nut left out.
Beam pattern looks uneven. Recheck lamp seating first, then adjust the aim against a flat wall.
App cannot connect. Turn on Bluetooth and Location Services on your phone (Android needs Location for Bluetooth scanning). Keep other strong signal sources away from the car.
Condensation inside the headlight. Temperature differences can cause light condensation, which is normal. Once the light has been on for a while and the internal temperature stabilizes, the moisture clears on its own. It does not affect brightness, performance, or lifespan.
