What angle should my projector headlights be at?

Question

A while ago I did a custom projector retrofit for my jeep. I really love the technology and it makes driving in the dark much easier and safer.

Making the parts for the projector was not to bad, but I have had a really hard time finding a good angle for my lights that gives me good throw without blinding other drivers. I have tried everything from completely flat, to probably about 10 degrees from horizontal so I cannot really see that much.

Is there some recommended angle for projector headlights that I should adjust mine to? Just now I readjusted them to about 1.5 degrees from horizontal (that's from very rough measurements taken in my garage). Is 1.5 degrees a good angle or should I point them down more?

Thank you.

Answer 1

In order to aim projector lamps I use the same procedure with all of them.

AIMING PROJECTOR HEADLIGHTS

1. Align your car dead center in your driveway....the front and back of your car need to be perfectly aligned in the center..

2. Pull your car up to the garage door, as close as you can get without actually hitting the garage.

3. Put a piece of tape where the headlight beams hit the garage door.

   • This should only be small dot of light.

4. Pull you car back about twenty five feet or so. When backing the vehicle up, it is vital that you go in a straight line or else the beam will be swayed and your end result, not what you were looking for.

5. With tape Place a vertical line that intersects each piece of tape that you put on the garage where your headlight beams hit. I like to use a yardstick or a straight edge to make it perpendicular to the driveway. This line will be used to reference the angle of the lights right to left. This adjustment is just as important as the height of the beam.

6. Using the tape again, now place a horizontal line along the garage where the beams hit. They should both be the same height from the ground.

7. Using more tape now place a horizontal line 2.1" lower than the tape you just placed on the garage door

8. Next you will work on the lights individually. Block the beam from on side using a thick towel or just unplug it. And turn the lights on.

9. I'll start with the Drivers Side UP/Down: First bring the lower step of the cutoff to just below the lower of the two tape lines. This will set you at 2.1" lower than your headlight. DOT Specifications tolerance is 2.1" to 2.5" drop over 25'.

10. Now move to the Drivers Side Right/Left: The Vertical line on the drivers side of the garage should intersect the middle of the slant on the cutoff. This will take some patience but you'll get it. Just keep adjusting until you get it. Be aware that performing any Right/Left adjustments may in turn effect the Up/Down. If this is the case go back and keep everything set correctly.

11. Now it's time to move to the other side. Cover the Drivers side headlight with a thick towel and repeat the UP/Down and Left/Right procedure from the previous steps. Use the vertical line on the passenger side of the garage for intersecting the slant in the cutoff on the passenger side headlight beam.

Using this method takes a bit of patience but once it's done, you'll be very pleased with the results. Also, all the other drivers on the road will be very pleased with the results. And, when people are in the vehicle it will look very professional as if it came from the factory that way.

Hope this helps. You might want to print this out and take it with you while you perform the alignment on the lights. I keep these instructions in the tool box for reference still.

---

Original source for these instructions can be found here