Connecting Tractor With 7-Pole Round to Trailer With Electric Brakes
Updated 11/17/2025 | Published 12/21/2024
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Question:
Hello, I have the same situation to connect tractor 7 pin to 6 blade for car hauling trailer with electric brakes. Where I can order this converter ?
asked by: Sergey
Expert Reply:
Hi Sergey; it sounds like you have a 7-pole round on your tractor and then either a 6-pole round or 7-way blade on the trailer. The # 119178 you ordered will combine your brake light and turn signals so that is a good start.
Since there are no adapters available as is you will have to make one just like in the other question you looked at. You will need the # PK11700, # DW04914-1, and then # PK11893 (if the trailer has a 7-way blade) or # PK11609 (if the trailer has a 6-pole round). You can use the wiring diagram below to help match up the functions between them.
I'm also not sure how you're connecting your brake controller but you may want to pick up # 10-1-1 to run a separate brake output wire back to your connector. Alternatively, since you already have the # 119178 you could go ahead and install a completely separate 7-way blade (assuming that is what you need for the trailer) using the # ETBC7.
(click to enlarge)
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on Custom Fit Vehicle Wiring
Robin H.
11/17/2025
Hey Sergey, how did things go with building the adapter for your tractor and car hauler trailer? Your update could make it easier for others trying to match a 7-pole round to a 6-blade or 7-way blade setup.