well i hooked up the wire trailer side. yellow is left turn signal/stop light... green is right turn signal/stop... (gray????) white is ground... but the gray is dead(3rd to the right)... "does the truck harness come with park lights for the trailer???" u know when u move the light switch in the cab be for u hit the head lights the park lights come on and stay on... "y wont the trailer park lights work????..." mine on the trailer don't work....