How to Connect 7-Way to Blunt Cut OEM Wires on a 2017 Ram 3500

Question:

Lookin for trailer plug wire diagram for 2017 ram 3500 tradesman crew cab 6.4 hemi ? All have is the 7 wires visible. Thanks

asked by: Joseph L

Helpful Expert Reply:

I checked the online version of the owner's manual for your 2017 Ram 3500 and the only thing that it stated in regards to trailer wiring is that it is already run. Because of this and the picture you sent in it looks like someone may have modified the wiring on your Ram. I can give you some pointers on how to install a 7-Way but unfortunately I don't know what color wire is for what function in your picture.

What I recommend doing is installing a universal wiring connector like the Hopkins # HM40975-11998 and using a circuit tester like part # PTW2979 to see what wire is for what function on that wiring harness that you found. Just touch the end of the test to each wire while a buddy runs through the various functions (turning, brake, etc...) and take a note of what each one tests for.

Once you know the function of each wire you can simply connect the Hopkins wiring harness to the proper function (see attached photo) but keep in mind that the wiring colors may not match up.

expert reply by: Jon G