BTS installation guide · X3B35 / X3B40

F-150 Morimoto X3B third brake-light installation

Follow the original connection route, transfer the camera where fitted, and seat the new lamp with the correct clips and screws.

Before you begin.

This guide applies to X3B35 and X3B40 on the supported F-150 installation. Check the camera choice before opening the truck. You need a T20 Torx driver, a clean working surface and isopropyl alcohol for the mounting surface. Have the original instructions available; use an installer if you cannot confidently identify the wiring or release the trim.

X3B35 reuses the original camera. X3B40 is for trucks without that camera. Raptor owners: the separate factory red parking-light function is not retained.

X3B35 camera housing and X3B40 non-camera housing, as shown in Morimoto’s manual.
X3B35 camera housing and X3B40 non-camera housing, as shown in Morimoto’s manual.

1–4 · Remove the lamp and free the wiring.

1. Remove the four T20 screws and carefully draw the lamp away from the cab while supporting it.

The four T20 screw locations on the two original lamp styles.
The four T20 screw locations on the two original lamp styles.
Support the original lamp as it comes away from the cab.
Support the original lamp as it comes away from the cab.

2. Release the plastic retaining clips inside the cab opening by pressing them down as shown.

Original retaining clips, identified by the yellow arrows.
Original retaining clips, identified by the yellow arrows.

3. Move the connector wiring to the right and through the cab opening. Separate the connection and set the old light aside.

Disconnect the original lamp wiring and move it through the cab opening.
Disconnect the original lamp wiring and move it through the cab opening.

4. The factory connection shown below does not plug directly into the X3B. Return this wiring into the cab; the correct pigtail is reached from inside.

This exposed factory connection is not the X3B adapter connection.
This exposed factory connection is not the X3B adapter connection.

5–9 · Connect the pigtail and fit the mounting clips.

5. Inside the truck, gently ease the headliner down above the rear window.

Gently access the area above the rear window without creasing the headliner.
Gently access the area above the rear window without creasing the headliner.

6. Locate and unplug the original third brake-light pigtail behind the headliner.

The correct pigtail and connector behind the headliner.
The correct pigtail and connector behind the headliner.

7. Connect the supplied pigtail and seat its push clip. Feed the wiring through the cab hole and centre opening shown. Refit the headliner using its original clips and holes.

New pigtail routing and the push-clip location.
New pigtail routing and the push-clip location.

8. Squeeze the two plastic mounting clips in the cab opening and remove them. Keep them aside.

Release and remove the two original mounting clips.
Release and remove the two original mounting clips.

9. Fit the centre clips to the X3B if they are not already installed. Their tangs must face left and right across the lamp, not up and down. These clips are single-use; Morimoto supplies a spare set.

Correct left/right orientation of the X3B centre mounting clips.
Correct left/right orientation of the X3B centre mounting clips.

10–12 · Transfer the original camera, if equipped.

Without a camera: skip these three steps and continue with testing and sealing.

10. Unplug the camera at the rear of the original lamp. Remove the two camera-bracket screws and lift off the bracket.

Remove the original camera bracket and retain its hardware.
Remove the original camera bracket and retain its hardware.

11. Remove the factory camera and place it into the camera opening of the X3B35.

Transfer the original camera into the X3B35 housing.
Transfer the original camera into the X3B35 housing.

12. Reinstall the camera cover and screws, then reconnect the camera.

Camera cover, screws and connector refitted on the X3B35.
Camera cover, screws and connector refitted on the X3B35.

13–17 · Test first, then seal and fasten.

  1. If fitting the separate X3B01 rapid-flash module, complete the optional procedure below before final installation.
  2. Clean the truck’s mounting surface with isopropyl alcohol and let it dry completely.
  3. Confirm every connection, switch the truck on and check all lighting functions. Check the transferred camera where fitted. Only the two outer original screws are reused; the centre positions use clips.
  4. Give the mounting surface a final alcohol wipe. Peel the backing from the gasket only when you are ready to seat the lamp. The adhesive gasket is single-use, so align it carefully.
  5. Align the centre clips with the square holes, then press the light firmly into position. The clips may engage without an audible click. Reinstall the two outer original screws without overtightening: they thread into plastic.

Optional X3B01 rapid-flash module.

This accessory is sold separately. Its installation is included here because it appears in the manufacturer’s manual; it is not required for the standard lamp.

Optional X3B01 module; not part of the standard X3B lamp selection.
Optional X3B01 module; not part of the standard X3B lamp selection.
  1. Unclip the wiring harness from the rear of the X3B.
  2. Connect the module’s female connector to the light.
  3. Connect the light’s harness to the module’s male connector.
  4. Remove the backing from the module’s mounting tape and secure it to the back of the light or inside the lamp cavity.
  5. Switch on the truck and test all functions before final assembly.
Original module sequence: disconnect the harness, insert the module and reconnect.
Original module sequence: disconnect the harness, insert the module and reconnect.

Finish the rear of your F-150

XB tail lights · X3B third brake light · XB license-plate lights · All 2021–2023 F-150 upgrades · F-150 lighting buying guide

Written by BTS from Morimoto’s X3B35/X3B40 manual; all relevant instructional photos and original annotations are retained above. Source checked October 23, 2026. Open the complete manufacturer PDF. The PDF repeats some printed page numbers; the sequence here follows its actual eight pages.