Is the OEM Trailer Wiring Pattern the Same for Dodge Ford and GM vehicles

Question:

It has been proposed to me that there is a possible difference in the wiring pattern on a seven contact trailer connection on Dodge trucks and GM trucks and Ford trucks or is the pattern the same for all trucks reguardless of vehicle manufacture?

asked by: Steve G

Expert Reply:

The OEM wiring configuration of all Chevrolet, Dodge and Ford vehicles, as well as Nissan and Toyota, is the same, and is identical to the pattern shown in the photo I have attached. This is all based on wiring that has not been changed from the original configuration by the owner of the vehicle.

Many times we see vehicles come in with the wiring on the vehicle changed because the person has a trailer that is wired incorrectly. Instead of changing the trailer wiring to match the industry standard, the vehicle wiring is changed to match the trailer, essentially making that vehicle only compatible with that trailer or one similarly wired.

expert reply by: Robert G

click to enlarge

Fred C.

3/14/2020

If the wiring diagram you posted is the industry standard, why are there so many different variations posted by the major manufacturers? I have 3 trailers and 3 trucks with 7 blade RV trailer connectors and all of them have different wiring configurations.

Chris R.

3/15/2020

The wiring configurations for the 7-Way connectors on your trucks and trailers should be the same with regards to the function locations. The wire colors likely differ (there's a semi-standard here but a lot of times manufacturers do what they want) but the actual functions will be the same. For example the 9 o'clock pin on the truck's 7-Way will always be for left turn/brake lights.

Ben W.

8/19/2020

@ChrisR today I hooked my 2017 f350 up to a 2019 PJ gooseneck with electric over Hydraulic breaks. I couldn’t get the breaks to work. Another guy hooked up his newer model dodge And everything worked fine. I totally understand this could be problem with the wires in my truck but I’ve also been told that this happens sometimes and that there is an adapter I may need if I don’t want to rewrite the trailer. Any truth to this?

Jon G.

8/28/2020

@BenW If you're using the OEM brake controller on your 2017 Ford F-350 then the adapter you've heard about is part # HBA-CAM. Your OEM controller *should* work with an electric-over-hydraulic setup but sometimes they won't work and we have heard that this does help.

See All (11) Replies to Fred C. ∨

Peter

7/15/2024

I’m wiring a lance camper plug on my 2023 ram 3500 diesel. I bought a bed plug adapter from you. It plugs in behind the stock trailer plug wiring harness. When I attach my new camper plug to the wire for running lights, the lights come on, even though my lights are off on my ram. I can’t leave the lights on the camper lit all the time as it will run my battery down what is going on?