How to Determine Trailer Wiring Color Functions
Published 09/30/2015
Question:
Ive attempted to connect new lights to my boat trailer. Im confused by the wiring that runs from the lights having only four wires - red, blue, white and brown. Im trying to attach it to a small 7-pin round plug that obviously has yellow and green for left and right blinkers. What do I do?
asked by: Clint H
Expert Reply:
Since wire colors on trailer wiring aren't standardized you will need to test the wires on your trailer to determine their function before you can wire them to a trailer.
An easy way to do this is to use a 12 volt battery and a jumper wire to apply voltage to each wire to see then what circuits activate. I attached a picture that shows a wiring diagram of a 7-way for you to check out as well.
