24 Find a good ground for the black wire, either on the radiator mount or (as shown) on the alternator bracket. At this point, touching the yellow wire (not shown) to a power source will cause the actuators to extend. If you hear a humming noise from the actuators, that means they did not fully extend or retract, and you’ll need to adjust the length of the piston. (Rotate it clockwise to extend, counter-clockwise to shorten.) Now is also a good time to adjust how high the headlights sit when closed; do this using the adjuster screw in the new operating arm.