Properly aim auxiliary lights to increase visibility.
Many Harley-Davidson FL family models come equipped with stock auxiliary lamps — or passing lamps — mounted to the front forks. Other models may have them added as optional equipment. The auxiliary lights increase the forward light output and increase visibility for the rider. Aim auxiliary lights relative to the headlight to prevent blinding oncoming traffic and increase road illumination immediately in front of the bike.
1. Ensure that the tire pressure is correct for the year, make and model of the bike. Fill the fuel tank. Verify that the suspension is adjusted for the weight of the principal rider and that any normal ballast, such as items in the fork bag and saddlebags, is on the bike.
2. Park the bike on firm, level ground 25 feet from a wall. Have a helper mount the bike and hold it upright and level with the front wheel pointed straight forward.
3. Measure the height from the ground to the center of the headlight by using a tape measure. Use a marker to mark a horizontal line on the wall 2.1 inches lower than the headlight measurement.
4. Turn on the headlight high beam and draw a vertical line through the horizontal line at the center of the brightest part of the high-beam illumination area. Turn the headlight off.
5. Measure the distance between the horizontal centerline of the headlight and the horizontal centerlines of the auxiliary lights. Mark the horizontal centerlines for the auxiliary lights relative to the headlight marks on the wall by using a tape measure and marker.
6. Measure the distance between the vertical centerline of the headlight and the vertical centerlines of the auxiliary lights. Mark the vertical centerlines for the auxiliary lights relative to the headlight marks on the wall by using a tape measure and marker.
7. Loosen the turn signal mounting screws by using a ratchet and Allen driver. Remove the turn signals from the mounting bracket.
8. Loosen the auxiliary light adjuster nut by using a flare-nut socket and ratchet. Aim each auxiliary light so that the high-intensity light zone is just below and to the right of the corresponding auxiliary light marks on the wall.
9. Torque the auxiliary light adjuster nut to 18 foot-pounds by using a foot-pound torque wrench and flare-nut socket. Recheck the aim of the auxiliary lights after tightening.
10. Install the turn signals and start the screws. Make certain that the turn signal wiring fits properly in the wiring slot and that it is not pinched. Tighten the turn signal screws alternately to 36 to 60 inch-pounds of torque by using an inch-pound torque wrench and Allen driver.