What is the Difference Between a 4-Way and 7-Way Trailer Connector
Updated 04/13/2025 | Published 09/07/2015 >
Question:
What is difference between a 4 pin and 7 pin trailer connector?
asked by: Carl Z
Expert Reply:
A 4-Way trailer connector has the basic lighting functions only; running lights, left turn signal and brake lights, right turn signal and brake lights, and ground.
A 7-Way has these functions and a 12 volt circuit, a circuit for electric trailer brakes (requires a brake controller in the vehicle), and a reverse light or auxiliary power circuit.
There are other types of connectors as well. I have included a link to our help article that shows and explains the various connector types.

Danielle D.
5/13/2020
So I have a camper with a 7 round and a vehicle with a 4 flat pin. Can I just buy an adapter or will I not be able to use the brakes on the camper, only the lights?


William W.
5/26/2020
Is there an adapter available to go from a 7 pin wire connector on a 2014 ford truck F350 to a trailer plug which is a 9 pin? And if not whats different from a 7 way versus a 9 way? Thank You,


Joel M.
5/28/2020
Have Titan xd 2016 pro 4x has factory 7 way and 4prong wold like to get 7 way on a old car hauling trailer. Backup lights, brakes. Do you have plug ready for trailer, need to re wire and light whole trailer, and brain transplant for myself. Can you help me please? Thanks


Boris G.
7/29/2020
for a ford transit 250 which is what I need to install to connect a trailer with 2 axles with brakes, and where I could make an appointment to do the work with you. Thank you



Product Page this Question was Asked From
T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
- Custom Fit Vehicle Wiring
- Trailer Hitch Wiring
- Vehicle End Connector
- Converter
- No Tow Package
- 4 Flat
- Plug and Lead
- Plug-In
- Visible
- Tekonsha
more information >
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Dennis L.
5/8/2020
Can I get a plug and play trailer wiring kit that requires no cutting of wires to go with hitch from you for 2001 freightliner MT45 former snap on truck going to be used as off grid rv?