Where To Attach Blue Wire From 5 Wires on Trailer When Installing a 7-Way Connector
Question:
I have 5 wires from trailer to a 7 way blade. Where does the blue wire go?
asked by: Scott
Expert Reply:
When wiring a 7-Way on your trailer with 5 wires, your green wire will be right turn/brake, the yellow wire will be left turn/brake, the brown wire will be the taillights, and the white wire will be the ground. You will want to find out if the blue wire on your trailer is needed for 12-volt power for trailer accessories, for electric brakes, or for a reverse brake lockout, if your trailer has surge/hydraulic brakes.
Looking at the rear of the 7-Way connector, if you need the blue wire for electric brakes it would attach to the # 2 terminal at the 5 o'clock position. If you need it for 12-volt power, you will attach it to the # 4 terminal at the 1 o'clock position.
If you need the blue wire for reverse brake lockout you will attach it to the center pin of the 7-Way connector. You might want to test the center pin on the 7-Way, with a circuit tester, like part # PTW2993, on your vehicle to make sure it is wired for reverse lights.
The additional blue wire is tapped into the reverse lights on the vehicle to disengage the hydraulic trailer coupler (actuator) when the vehicle is reversing, thus turning off the trailer's brakes.
I am including a picture of a 7-Way trailer connector that will show the terminals and their function. Also, I am including a link to a FAQ page on trailer wiring.
Brian A.
3/21/2020
I have a five 5 wire trailer connected into a seven pin plug. My colours are Blue, yellow, Brown, white and black. Which wires are wired to which in the seven 7 pin plug configuration.
Chris R.
3/22/2020
Brad B.
4/17/2020
My truck only has a light blue wire for CHMSL no dark blue for trailer brakes.Got a curt Echo, my 7 pin connection has a dark blue and red wire left to hook up somewhere and I only have on my truck1 light blue wire left. Help! Please!
Chris R.
4/18/2020
Steve M.
7/13/2020
I have a 2014 Ford Edge and need to install a 5 flat connector to the vehicle. I can't determine which wire to tie into. There is a large plug connection under the rear end and three pins had continuity to the back up light but neither worked as it should.
Chris R.
7/17/2020
Products Referenced in This Question
Product Page this Question was Asked From
Pollak Black Plastic, 7-Pole, RV-Style Trailer Connector - Trailer End
- Trailer Wiring
- Trailer Connectors
- Trailer End Connector
- Plug Only
- 7 Round - Blade
- Pollak
more information >
Featured Help Information
Miscellaneous Media
Continue Researching
- Article: Trailer Wiring Diagrams
- Article: Wiring Trailer Lights with a 5-Way Plug (It's Easier Than You Think)
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)
- Q&A: Connecting 5 Wires From a Trailer to a 7-Way Trailer Connector
- Shop: Trailer Hitch
- Q&A: Recommended Trailer Wiring for 7-Way with Only 5 Wires
- Shop: Trailer Wiring
- Shop: etrailer Trailer Hitch Receiver - Custom Fit - Matte Black Finish - Class III - 2"
- Shop: etrailer Trailer Hitch Receiver - Custom Fit - Matte Black Finish - Class III - 2"
- Video: A Closer Look at the Roadmaster Tow Defender Protective Screen on a 2021 Jeep Grand Cherokee
- Video: All You Need to Know About the 7-Pole Blade to 5-Pole Flat Connector Wired Trailer Adapter
- Q&A: Converting Trailer from 5-Way Connector to a 7-Way by Function
- Article: Wiring Trailer Lights with a 6-Way Plug (It's Easier Than You Think)
- Search Results: bx7365 alpha
- Video: The Low-Down on the 7-Pole Rubber Socket Boot
- Q&A: Replacing 6-Way on Trailer With 7-Way Connector
- Article: Breakaway Kit Installation for Single and Dual Brake Axle Trailers
- Video: What to Know About the Demco Hydraulic Brake Actuator w/ Electric Lockout
- Video: All You Need to Know About the 24" Long Safety Chain with 1/4" S-Hook
- Search Results: surge brake reverse solenoid
- Article: How to Bleed Your Trailer Surge Brakes
- Shop: Trailer Hub and Drum Assembly - 3,500-lb Axles - 10" Diameter - 5 on 4-1/2 - Pre-Greased
- Shop: Easy Grease Trailer Hub and Drum Assembly for 3.5K Axles - 10" - 5 on 4-1/2 - Pre-Greased
- Shop: Hopkins Plug-In Simple Vehicle Wiring Harness for Factory Tow Package - 7-Way and 4-Flat Connectors
- Shop: Curt Trailer Hitch Receiver - Custom Fit - Class III - 2"
- Video: Curt T-Connector Vehicle Wiring Harness Installation - 2023 Nissan Rogue
- Video: Mount: T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector on a 2023 Nissan Rogue
- Shop: Hook Probe Circuit Tester
- Q&A: Do I Have to Adjust the TruRyde Electric Trailer Brakes?
- Q&A: What Function is Carried on Center Pin of 6-Way Round Trailer Connectors
on Trailer Wiring
Ronnie L.
1/28/2020
where do i attach the blue wire from 5 wire on my trailer when plugging it into a 5 to a 4 adapter on my bike . The trailer has no brakes but it does have 3 lights on the back that don’t work when it’s plugged up but all the other lights do . Is it possible to tie the blue wire in with the brown .