How To Wire a Trailer Tail Light with Yellow, Black, Red, and White Wires

Question:

I have taillights that have 4 wires blk red yellow and white. What is each color

asked by: William

Expert Reply:

The best way to find out what each wire is for on your tail light is to take a 12 volt power supply and apply that to each of the wires to see which bulb it illuminates. I cannot really give you an exact function for each color as it could vary from manufacturer to manufacturer.

With that being said, we have the Fusion LED Combination Tail Light Bar part # STL264RB which contains white, black, red, and yellow wires. The functions of these colors on this lights are as follows. This may be similar to what you have but it will be best to test with 12 volt power before making your connections.

Black: Tail
White: Ground
Red: Step/Turn
Yellow: Backup

expert reply by: Conner L