Identify the trailer plug type and pin layout
Disconnect the vehicle battery before starting
Strip the wire ends cleanly
Match each trailer wire to the correct function
Ground wire to the white terminal or pin
Tail/running lights wire to the brown terminal or pin
Left turn and brake wire to the yellow terminal or pin
Right turn and brake wire to the green terminal or pin
Electric brake wire to the blue terminal or pin
12V power wire to the black or auxiliary terminal or pin
Reverse/backup wire to the purple terminal or pin
Connect each wire to the corresponding terminal
Secure all connections tightly
Use heat shrink or electrical tape on exposed connections
Test all lights and functions with a trailer tester or tow vehicle
Recheck grounding if any light does not work
Bundle and secure the wiring away from moving or hot parts