bing tracking image
Q & A Icon

How to Wire a Freightliner 7-Way to Match Utility Trailer 7-Way Functions  

Updated 10/21/2025 | Published 09/07/2023

Question:

I am trying to set up a 2019 Freightliner M2 trailer 7 way port to be compatible with a utility trailer with electric brakes. Is there a conversion kit or guide that can assist me ?

0

Expert Reply:

The best way to make your Freightliner compatible with a trailer 7-Way is to test the functions with a circuit tester # PTW2993 and match sure they match. I'm attaching pin-out diagrams of both the trailer and vehicle 7-Ways that you can use as a guide to make your connections - just be sure to wire everything up by function and not by the wire color. You will be able to gain access to the wiring connections through the back of either 7-Way, either by moving the sleeve out of the way or by removing a screw that holds a housing together.

If your trailer doesn't already have a 7-Way then I highly recommend using the Junction Box Kit # 3430001-JBK and 7-Way Wire Connector # H20044 to do so. I'm attaching an installation video of the connector for you to check out.

expert reply by:
0
Jon G
Trailer-Side 7-Way Functions
Trailer-Side 7-Way Functions
(click to enlarge)
Vehicle-Side 7-Way Functions
Vehicle-Side 7-Way Functions
(click to enlarge)
Dan B. profile picture

Dan B.

9/23/2025

Semi trailer wiring runs on a different system than a RV plug, they are not compatible.

Jon G. profile picture

Jon G.

9/23/2025

@DanB Do you mean volts-wise, or that the pinouts aren't the same?
Tyrel profile picture

Tyrel

10/21/2025

@JonG Semi 7 pin is different than RV 7 Way plugs. Semis use a separate circuit for brakes, left turn, and right turn. You need a converter to get the brakes and turn signals on the same circuit to add a 7 way RV plug.
Jon G. profile picture

Jon G.

10/21/2025

@Tyrel Got it. So they would just need the Hopkins Tail Light Converter # HM48847 as well to make sure all of the functions are there.

Product Page this Question was Asked From


Q & A Icon

Continue Researching

See More Q&A Expert Answers >>