In the trailer wiring diagram and connector application chart below use the first 5 pins and ignore the rest. If your truck has a built in 7 pin socket but you only need 5 of the pins.

Trailer Plug Wiring Diagram 7 Way Flat Wiring Diagrams
7 pin pigtail wiring diagram. If your vehicle is not equipped with a working trailer wiring harness there are a number of different solutions to provide the perfect fit for your specific vehicle. Each component ought to be set and connected with different parts in particular manner. It can transfer electricity better hence the connector is suggested for higher level electric in the car. 7 pin trailer wiring diagram with brakes 7 pin flat trailer wiring diagram with brakes 7 pin rv trailer wiring diagram with brakes 7 pin trailer wiring diagram with brakes every electrical arrangement is made up of various different parts. Phillips 7 pin trailer connector wiring diagram wiring data diagram trailer pigtail wiring diagram by bismillah. Use the 7 pin connector anyway see below and just leave out the last 2 wires.
Wiring recommendation for the pollak metal 7 pole pk12703. As you can see the 7 way round pin trailer connectors do not use the typical pin functions. Complete with a color coded trailer wiring diagram for each plug type this guide walks through various trailer wiring installation solution including custom wiring splice in wiring and replacement wiring. This trailer pigtail wiring diagram version is more acceptable for sophisticated trailers and rvs. Trailer light wiring diagram 7 pin plug pro latest lights 7 way wiring diagram inspirational 6 way flat trailer wiring. Does the ground need to be re done when installing a new trailer connector.
Wiring extension for flat towing a vehicle behind monaco rv with 7 way trailer connector. I have also included a picture that shows the typical wiring diagram of a 7 way round pin trailer side connector. 7 way female to 7 way female adapter recommendation. 7 way tractor trailer plug wiring diagram pin great pigtail 7 way semi trailer wiring diagram semi trailer harness today wiring schematic diagram. 7 way trailer connectors are used by the following vehicle types. 7 way trailer connectors are found on most recreational vehicles and are used on larger gooseneck 5th wheel boat and utility trailers.
I have included a link to it. On most recreational vehicles. Large 5th wheel trailers. I do have a handy trailer wiring faq article that would be perfect for you. 7 pin trailer wiring diagram with brakes. If not the arrangement will not function as it ought to be.
No power to 12 volt pin on 7 way of a gm truck. They supply power to the taillights turn signals brake lights trailer brakes reverse lights auxiliary power and include a ground connection. 7 way trailer wiring diagram is explained in details in the picture and the table below. They come in two variations 7 way round and 7 way with rv blades.