Just bought undertail kit, not sure what wires do what. Tail light and blinkers are the same light. Lights came with these wires Red, Black, Blue, Yellow. Please help.

 

it didnt come with instructions?

 

try this:

red: positive taillight (+)
black: negative taillight (-)
blue/yellowositive blinker

Try blue and yellow to see wich color is left and right.

Blinkers use black wire for ground, so the green wires (negative blinker) are no longer used.

 

if its like the stock colors then...blue is right and yellow(or orange on an f4i) is the left side.

take a picture of the wiring in the inside if you want that may help.

 

Thanks i got the lights working, sorry didn't get back sooner, had knee surgery.