Lets talk about the differences in the 2 lighting types. A trailer with a 5 wire harness has connections for marker brake and signal lights as well as an electric braking system.

Universal Trailer Harness
Trailer wiring harness 5 wire to 4 wire. Here is a picture gallery about 5 wire to 4 wire trailer wiring diagram complete with the description of the image please find the image you need. Suzco 25 foot 4 wire 4 flat trailer light wiring harness extension kit 4 way plug 4 pin male female extension connector wishbone style with 18 gauge white ground wire with sae j1128. Install a 4 way trailer connector on your vehicle with this wiring harness with tail light converterharness splices into existing wiringsmt construction ensures superior performance. By reducing a 5 wire to a 4 wire you eliminate the connection for the trailers brakes. Provides a 4 pole flat trailer connector for the vehicle compatible with 5 pole 6 pole and 7 pole adapters sold separately hardwires to existing harness behind tail lights solid one. 5 way trailer harness connects to your tow vehicle to control trailer light functions ideal for marine trailers with hydraulic or surge brakes wishbone style harness comes with 2 tail.
5 pin trailer wiring harness with regard to 5 wire to 4 wire trailer wiring diagram image size 646 x 878 px and to view image details please click the image. Wishbone style harness comes with 2 tail light wires split for simple wiringauxiliary wire signals trailer. If your trailer is significantly heavy and is at the upper limits of the towing capacity of the vehicle. Free shipping on your first order shipped by amazon. Nothing is the same except you tow the trailer. Import lighting aka 5 or more wire.
Domestic lighting aka 4 wire. 5 way trailer harness connects to your tow vehicle to control trailer light functions. Trailer wiring can be confusing. 45 out of 5 stars 360. This is where your turn signals and brake lights are combined on the same wire and bulb.