What Does Blue Wire on 7-Way Upgrade Kit Connect to for Curt Echo Brake Controller?
Updated 09/29/2025 | Published 09/03/2025
Products Featured in This Question
Question:
I want to convert my 4 pin plug on 2004 Honda Pilot to 7 pin plug kit ETBC7L and use the Curt Echo Wireless brake controller part C51180. I’m confused what the vehicle side plug Blue Wire is connected to on the vehicle if I’m using a wireless brake controller .
asked by: John W
Expert Reply:
Hey John!
I completely get where you're coming from. The 4-Way/7-Way that comes with the 7-Way RV Upgrade Kit # ETBC7L has provisions for a brake controller that mounts inside the vehicle, but since you'll be using the Curt Echo # C51180 you won't be using that pin. We just have the wiring diagram on the page so people know what that wire is there for.
The black wire that comes with the upgrade kit will run from the black wire on the adapter up to your battery for 12V power, and that's the only wire that you'll need to run anywhere.
What drew you to the Curt Echo?
(click to enlarge)
Product Page this Question was Asked From
7-Way RV Upgrade Kit for Trailer Brake Controller Installation - 12 Gauge Wires
- Accessories and Parts
- Trailer Brake Controller
- Installation Kits
- etrailer
more information >
Continue Researching
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Q&A: How to Use a Curt Echo Wireless Brake Controller on a Vehicle w/a 4-Way Connector
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)
- Article: Brake Controller Installation: Starting from Scratch
- Q&A: Can I Use a 4 Way Vehicle Connector with 7 Way Adapter and the Curt Echo Brake Controller?
- Q&A: What Parts Do I Need To Add a 7-Way To A 2024 Toyota Highlander SLE Hybrid
- Article: Trailer Wiring Diagrams
- Q&A: Comparing the Universal Installation Kit # ETBC7 and the 7-Way RV Upgrade Kit # ETBC7L
- Q&A: What is the Difference Between a 4-Way and 7-Way Trailer Connector
- Q&A: My Vehicle has a 4-Pin Trailer Plug, but Trailer has 7-Pin Trailer Plug
- Article: Towing a Trailer? Let's Talk About Brake Controllers
- Article: How to Measure for Trailer Hitch Drop
- Q&A: 4-Way to 7-Way Adapter Recommendation for Installing Curt Echo Brake Controller
- Article: How to Choose the Right Trailer Hitch Class
Jon G.
9/29/2025
Hey John, did the explanation about the wiring help you with your setup? I'm curious to know what drew you to choose the Curt Echo, as your experience could help others considering a similar upgrade.