What wire color and circuit number feeds the Ford Bronco backup lamps?

Circuit 140, a black/pink (BK/PK) wire, feeds the backup lamps with 12V in reverse. Ground is circuit 57, black (BK).

Which connectors serve the left and right backup lamps?

The left backup lamp connects at C433 and the right backup lamp at C434. On the Bronco, circuit 140 passes through C406 (left) and C405 (right) before reaching the lamps.

How is the trailer backup lamps relay wired on F-Series trucks?

On trailer tow F-Series trucks, the relay in the trailer relay box receives circuit 140 BK/PK (12V in reverse) via C149 and 12V power on circuit 37 Y from Power Distribution (pages 13-2, 13-8). When energized, it outputs circuit 963 R/Y through C149, C424, and C417 to the trailer backup lamps. Its ground is 57 BK through splice S104 to G100.

Where does the backup lamp circuit ground on the Bronco?

Both lamps ground through circuit 57 BK: left via splice S406 and right via S405, joining at splice S401 and going to ground G100 (see grounds, page 10-5).

What other circuit branches off the backup lamp feed?

A branch of circuit 140 BK/PK goes through splice S232 and connector C202 to the Automatic Day/Night Mirrors circuit, shown on page 125-1.

Home/ Registry/ Ford/ Bronco/ 1992-1996/ “Buckin Bronco”/ Photo supermotors.net/registry/media/1136387

Ford Bronco & F-Series Backup Lamp Wiring Diagram 93-3 – Trailer Relay, C433/C434

Ford EVTM page 93-3: backup lamps wiring diagram with trailer relay and Bronco/F-series lamps

‹ ›

Backup lamp wiring diagram showing trailer backup lamps relay and left/right backup lamps for Bronco, F-series and flare side bodies.

AI caption July 2018 · Photo 330 of 386

This is page 93-3, "Backup Lamps," from a Ford factory wiring diagram set covering both Bronco and F-Series trucks. It shows the backup (reverse) lamp circuit downstream of connector C103 (continued from page 93-1). Circuit 140 BK/PK (black/pink) carries 12V in reverse through splices S116 and S232, connectors C202 and C205, with a branch feeding the Automatic Day/Night Mirrors circuit (page 125-1). The Bronco branch runs through splice S424 to connectors C406 and C405, then to the left and right backup lamps at C433 and C434, grounding via circuit 57 BK through S406/S405 to S401 and ground G100 (grounds on page 10-5). The F-Series branch runs through S254; a "Trailer Tow Only" leg feeds the Trailer Backup Lamps Relay in the trailer relay box via C149, powered by circuit 37 Y from Power Distribution (pages 13-2, 13-8), outputting circuit 963 R/Y through C149, C424, and C417 to the trailer backup lamps, with ground through S104 to G100. A Flare Side leg passes through C401 and S426 to the backup lamps at C433/C434, grounding through S404 to G100 (grounds page 10-4). Wire colors, circuit numbers, splices, and voltages are labeled throughout.

Is this accurate? Sign in to help verify it.

Frequently asked questions

What wire color and circuit number feeds the Ford Bronco backup lamps?: Circuit 140, a black/pink (BK/PK) wire, feeds the backup lamps with 12V in reverse. Ground is circuit 57, black (BK).
Which connectors serve the left and right backup lamps?: The left backup lamp connects at C433 and the right backup lamp at C434. On the Bronco, circuit 140 passes through C406 (left) and C405 (right) before reaching the lamps.
How is the trailer backup lamps relay wired on F-Series trucks?: On trailer tow F-Series trucks, the relay in the trailer relay box receives circuit 140 BK/PK (12V in reverse) via C149 and 12V power on circuit 37 Y from Power Distribution (pages 13-2, 13-8). When energized, it outputs circuit 963 R/Y through C149, C424, and C417 to the trailer backup lamps. Its ground is 57 BK through splice S104 to G100.
Where does the backup lamp circuit ground on the Bronco?: Both lamps ground through circuit 57 BK: left via splice S406 and right via S405, joining at splice S401 and going to ground G100 (see grounds, page 10-5).
What other circuit branches off the backup lamp feed?: A branch of circuit 140 BK/PK goes through splice S232 and connector C202 to the Automatic Day/Night Mirrors circuit, shown on page 125-1.