Do Trailer Reverse Lights Require Two or Three Wires to be Powered

Question:

Hello! I would like to add backup lights to my utility trailer which has a 4 pin plug. I understand that I will have to cut the 4 pin plug off and wire a 7 pin plug. I will need a two-prong pigtail for each light correct? I will plug in the existing three prong plug and the new two prong plug into STL211RCB. Do I need to ground the new two prong plug? Do I then just connect the two white wires from the two lights and run that up to the center pin of my 7 pin plug? Is there a better solution? Thank you very much for your time.

asked by: Matt

Expert Reply:

Reverse lights like the part # STL211RCB only need power and ground to function. You would not need three wires ran to the light assembly. Power would need to come from the reverse light circuit of the tow vehicle but you can ground the lights to the trailer frame or using wire to run back to ground of the trailer wiring. The version of the light I would recommend instead though is the part # BUL10CB since this is just a reverse light.

For pigtail harnesses you'd want either the # A45CB for a straight plug or part # A49PB for a right angle plug.

expert reply by: Jameson C