Determining Wire Functions on Trailer with Non-Standard Wire Colors

Question:

Hi i have a boat trailer with 5 wires and im confused as to which goes where to a round 7 plug.the colours i have are red,yellow,white,black,blue.it is not a braked trailer and the blue is throwing me. also i have no green for other indicator. Thanks

asked by: Luke T

Expert Reply:

Since the wiring on your trailer doesn't use the standard colors the best method for determine their function is to simply apply 12V power to each one to see which lights they activate. Once you determine the function for each of the wires you will just need to connect them to the corresponding terminal on the 7-Way connector. I have attached a wiring diagram for a 7-Way that you can use for reference.

expert reply by: Chris R