Standard 7-Way Wiring For Vehicle Side Trailer Connection


2004 dodge Ram 3500 Dually electrical connection works with my 2010 Keystone Montana fifth wheel camper, works with my 20 foot Gooseneck Ponderosa cattle trailer and works with my 24 foot Wil-Ro flatbed trailer. Why does my truck not work with my best friends who has a Chevrolet truck and a 24 foot flatbed trailer when hooked to it the brakes are locked solid and all 8 wheels slide also a friend borrowed my 24 foot trailer and he had to change the wiring to enable him to pull it with his Ford truck the same problem. Is this problem in the truck type or trailer type? and if possible what can be best changed to make all units to work with my truck?


Expert Reply:

I don't know which truck or trailer isn't wired standard, but it sounds like with multiple trailers working on your vehicle that your friend's truck and trailer are wired wrong, but to fit each other. I've attached a picture of what each of the 7 pins are set to function when set up with the standard configuration. I've also attached an article on trailer wiring to help. I suggest using a circuit tester like # PK12741 to help you determine if your truck is wired correctly and what function is off if not wired correctly for standard trailer use. I recommend steering away from looking for color connections to the wires, but rather focusing on the function of the wires and their correct connection positions.

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expert reply by:
Jason S

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