How To Rewire A 9-Pin Connector To A 7-Pin Connector
Updated 12/01/2025 | Published 10/31/2025
Question:
Howdy! We had a client show up with what looks like a European bike rack that has a big circular 9 pin connector, kind of a twist lock. Any thoughts or direction would be most grateful to connect to a circular 7 pin on vehicle side. Thank you
asked by: Tony R
Expert Reply:
Hi Tony!
Been quite a while since anyone asked me about a 9-pin connector. It's possible that is a European connector, but typically they use a 7-way that's wired differently than ours or a 13-pin. Either way, the only way to swap that over to a standard 7-way that we use over here is to test each wire for function. I did include an image of how a 9-pin it typically wired, which should help.
Once you have the functions figured out, you would just need to cut that plug off and hook everything up to a standard 7-way, like the Pollak Black Plastic, 7-Pole, RV-Style Trailer Connector - Trailer End # PK12706.
What kind of bike rack is it?
(click to enlarge)
(click to enlarge)
Product Page this Question was Asked From
Curt Heavy Duty Forged Ball Mount for 2" Hitches - 1" Rise - 2" Drop - 17,000 lbs
- Trailer Hitch Ball Mount
- Fixed Ball Mount
- No Ball
- Steel Shank
- Drop - 2 Inch
- Rise - 1 Inch
- Fits 2 Inch Hitch
- 17000 lbs GTW
- CURT
more information >
Continue Researching
- Q&A: How to Make a 9 Pin to 7-Way Adapter for Connecting Semi Truck to Trailer
- Q&A: Soft Start Recommendation for Furrion RV Air Conditioners
- Q&A: Can TowSmart Adjustable Ball Mount be Used with Gen-Y Voyager Torsion Flex Ball Mount
- Article: How to Measure for Trailer Hitch Drop
- Q&A: Does a Trailer Junction Box Have to be Used when Switching from 4-Way to 7-Way Trailer Connector
- Q&A: Can A-60 Actuator be Locked
- Q&A: Replacement AC Unit for a Coleman Mach 15 model 48254C869
- Q&A: Difference Between RhinoEXTREME and RhinoFLEX RV Sewer Hose
- Article: Which Hitches are Made in the USA
- Article: Trailer Wiring Diagrams
- Article: Ball Mount Basics: Weight Capacity, Class, and Size
- Article: Types of Trailer Hitches: How and Why to Use Each
- Article: Is It Illegal to Leave My Hitch on My Truck?
- Article: Best 5th Wheel to Gooseneck Adapters (2023)
Lazer S.
12/1/2025
Hey Tony, did you end up figuring out the wiring on that 9-pin connector for the bike rack? Knowing what worked could help others who run into the same type of plug. Your update could make it easier for the next person trying to match a European connector to a 7-way.