Hey y’all does anyone know what color wire under the dash goes to the reverse lights , I have a 72 f250 c/s that had a utility box when I bought it I have since tracked down a color matching bed. Everything except the reverse lights work any info helps.

 

...BK/R FROM BACK-UP SWITCH---CIRCUIT 140B
BROWN FROM TAIL-LIGHT---CIRCUIT 285---

 

Here are some of the 1972 wiring diagrams, you can look at all the wiring diagrams here:

Ford Truck Technical Drawings and Schematics - Section H - Wiring Diagrams (fordification.com)

 

I did my looking on my 1971 diagram in a hurry & got one wire kolur' wrong...
The 285 brown is wrong info . 285 is a tail or brake lamp.......
Ok........find the back up switch , my shifter hits it on the column . Trace the wire to the dash........
Find the back-up lamp & trace the black with red stripe wire to the dash ......... BRILLIANT........

 

Thank you was able to get them working

 

What was wrong with them and how did you fix them? In case someone has the same issue.

 

One I wired them onto a switch panel I had under the dash and had a issue with them grounding so to help I pulled the inner light housing out and added a small washer behind them and no problems after that