Install the dedicated F-150 C1R harness

DD7649 / DD4150 · 2021–2023 Ford F-150

This is the F-150 C1R procedure, including both tail-light signal connections. It is not the generic C1 Sport installation. Have an 8mm socket ready, park securely and confirm the receiver has an open back before starting.

1. Remove both factory tail lights

Lower the tailgate. Remove the two driver-side retaining bolts with an 8mm socket, then pull the lamp free of its ball clips. Disconnect the two plugs highlighted in the photo and set the lamp aside. Repeat on the passenger side.

Remove the tail light and disconnect the two factory plugs shown in blue.
Remove the tail light and disconnect the two factory plugs shown in blue. View full size

2. Choose the correct signal harness

Compare the factory tail-light functions with the original selection table. Choose the matching supplied signal harness. Its shorter branch from the AMP connector goes to the driver side; do not select by appearance alone.

Compare the supplied tail-light signal harnesses before connecting either side.
Compare the supplied tail-light signal harnesses before connecting either side. View full size
Select the signal harness using the factory tail-light function table.
Select the signal harness using the factory tail-light function table. View full size
The shorter branch from the AMP connector goes to the driver side.
The shorter branch from the AMP connector goes to the driver side. View full size

WH0244-1 · 4-pin

Halogen without Blind Spot

WH0244-2 · 12-pin Key A

LED without On Board Scale

WH0244-3 · 12-pin Key B

LED with On Board Scale

WH0244-4 · 6-pin

Halogen with Blind Spot

3. Connect the driver-side signal branch

Connect one lead of the shorter branch inline with the matching factory harness. Route the remaining signal harness down through the tail-light pocket beside the original loom.

Connect the short signal-harness branch inline, then route the remaining harness down through the pocket.
Connect the short signal-harness branch inline, then route the remaining harness down through the pocket. View full size

4. Refit the driver-side lamp

Reconnect the upper factory plug shown by the blue arrow. Connect the remaining signal-harness lead at the lower connection highlighted in red. Seat the lamp’s ball clips and reinstall its two original bolts.

Reconnect the driver-side upper factory plug and the remaining signal-harness lead.
Reconnect the driver-side upper factory plug and the remaining signal-harness lead. View full size

5. Route across above the frame rails

From below the vehicle, bring the remaining harness toward the passenger side, over the two frame rails beside the spare tire as illustrated. Keep the routing clear of moving or hot parts.

Route the harness over the two frame rails beside the spare tire.
Route the harness over the two frame rails beside the spare tire. View full size

6. Bring the harness into the passenger pocket

Feed the signal-harness branch up through the passenger-side tail-light pocket.

Bring the harness up into the passenger-side tail-light pocket.
Bring the harness up into the passenger-side tail-light pocket. View full size

7. Connect and refit the passenger-side lamp

Connect a signal-harness lead inline with the matching factory plug. Reconnect the upper factory plug and the other signal lead at the indicated lamp connectors. Seat the lamp and reinstall its two bolts.

Connect the passenger-side signal harness and upper factory plug before refitting the lamp.
Connect the passenger-side signal harness and upper factory plug before refitting the lamp. View full size

8. Optional: disable SafetyStrobe

For steady brake-light operation, the manufacturer directs you to cut the designated purple wire loop on the C1R harness. Leave it intact to retain SafetyStrobe. Identify the exact loop in the diagram before making this optional, irreversible cut.

The designated purple loop controls the optional SafetyStrobe disable procedure.
The designated purple loop controls the optional SafetyStrobe disable procedure. View full size

9. Disconnect the rear of the trailer socket

Under the bumper, release the factory harness from the rear of the 7-pin trailer connector.

Disconnect the factory trailer wiring from the rear of the 7-pin bumper socket.
Disconnect the factory trailer wiring from the rear of the 7-pin bumper socket. View full size

10. Open the signal harness AMP connection

Locate the AMP connector near the middle of the tail-light signal harness and remove its protective cap.

Remove the cap from the AMP connection in the tail-light signal harness.
Remove the cap from the AMP connection in the tail-light signal harness. View full size

11. Join the two harnesses

Connect the female AMP plug on the tail-light signal harness to the male AMP plug on the C1R HitchMount harness.

Join the tail-light signal harness to the HitchMount harness at the AMP connection.
Join the tail-light signal harness to the HitchMount harness at the AMP connection. View full size

12. Connect the inline trailer harness

Fit the C1R harness between the factory trailer loom and the rear of the bumper’s 7-pin socket.

Install the HitchMount harness inline behind the factory 7-pin socket.
Install the HitchMount harness inline behind the factory 7-pin socket. View full size

13. Feed the DT connector through the receiver

Route the DT end through the open back of the hitch receiver to the front. If the receiver is closed or obstructed, stop and confirm the correct mounting solution; do not assume this guide authorizes receiver drilling.

Feed the DT connector through the open back of the receiver.
Feed the DT connector through the open back of the receiver. View full size

14. Connect the C1R lamp

Remove the DT connector’s protective cap and plug it into the C1R pod.

Remove the DT connector cap and connect the C1R pod.
Remove the DT connector cap and connect the C1R pod. View full size

15. Seat the HitchMount

Push the lamp and mounting sleeve into the receiver until the side clips snap into place. Check that it is retained securely.

Push the HitchMount into the receiver until both retaining clips engage.
Push the HitchMount into the receiver until both retaining clips engage. View full size

16. Test and secure the wiring

Verify the White reverse light, low-output Red running light and Red brake function. Carry out the reverse check with the vehicle secured and the area behind it clear. Check for trailer-system warnings, then secure the harness with the supplied zip ties.

Check the installed lamp’s reverse, running-light and brake-light functions.
Check the installed lamp’s reverse, running-light and brake-light functions. View full size

17. Remove it when the receiver is needed

Press both side clips and slide the light out. Disconnect the DT plug, reinstall its protective cap and secure the connector clear of the receiver until the light is used again.

Optional locking-pin installation

A locking pin is not included. To use one, Diode specifies removing the circular sections of both retention tabs, connecting and inserting the HitchMount, then aligning and sliding the pin through. Watch the manufacturer’s close-up procedure before modifying the sleeve.

Get the correct kit or replacement harness

View the complete DD7649 F-150 C1R kit →

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