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.
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
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
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
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 >
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Steve S.
8/8/2020
I have been attempting to rewire trailers for years. Today was the day that went to this site, found the diagram above, and copied it. Everything works! First time for this shade tree mechanic wanna be. Thank you so much for proving the picture with the colors going exactly where they need to go!