How to Aim Your Headlights

It is now the dead of winter and you found a brand new set of Euro-spec headlights for your classic Alfa. You have even squandered those precious few daylight hours installing them and are marveling at how well they illuminate the road. Oops, and the trees tops. Sigh. Those are just the low beams. Well, don’t despair, it’s just that the aim is wrong, that’s all. Time to correct the condition, and you can aim your Euro-spec headlights on your own, without a machine.

• A very dark area with a vertical wall you can drive right up to and about 25-35 feet of level room, measured perpendicular to the wall
• Chalk (for drawing on the wall)
• Cardboard or similar opaque material (to cover lights not being adjusted)
• Tools for adjusting lights (a Phillips screwdriver + ??)
• A tape measure (or similar)
• Covers/protectors (these lights are expensive!)
• Warm clothes (for you, it’s winter!)

Prep the car –

• Fill the gas tank
• Equalize tire pressure
• Put a normal load in the car (your weight in the driver’s seat + weight for any regular passengers)
• Install the headlight protectors

• Put the car’s nose right up close and perpendicular to the wall
• Rock the car side to side to level the suspension

• Line "A" - Vertical, at the center (measured side-to-side) of the car
• Line "B" - Horizontal, at the same height as the vertical centers of the headlights
• Lines "C" - Vertical, at the horizontal centers of each lamp (2 lamps = 2 lines, 3 lamps = 3 lines, etc.)
• Line "D" - Horizontal, parallel to Line "B", 3 inches below "B"

• Keeping the car perpendicular to the wall, back it up until the lights are 25 feet away from the wall
• Keep the engine running fast enough (and probably the heater, too)

• Turn on the High beams
• Cover all but one light (usually one of the center high beam lights on a 4-headlight system)
• On the uncovered light, put the center of the high intensity zone on the intersection of Lines "B" and "C" (using the appropriate Line "C")
• Move the cover and repeat high beam adjustment until all lights are adjusted

This will give you a good initial aim. You should "tweak" it if, after driving for a while, the low beams seem to be too high (or too low). Now comes the balancing act - trying to avoid shining your new (brighter) lights in someone's eyes, but giving yourself the best (highest) light pattern possible. Putting the light pattern horizontal cut off at or below the top of the trunk lid of the sedan on the road in front of you is a good measure. Keep it a little conservative, though, the last thing you want to do is attract the attention of the local law officers.

This whole process can take about 30 minutes, make sure the gas tank is full and the engine is running so the battery is not drained. Keep in mind that you found that "dark", probably lonely, place to adjust your lights - it just might be a difficult place to find a jump.

No, you didn't use Line "A". It’s there because it's easy to locate and draw (where's the Alfa badge on your grill?) and it gives you some confidence in locating the other vertical lines (always start with a success – a good philosophy). To locate the other vertical lines, you can draw line "A" and measure out the distance for each lamp (Lines "C"), after measuring those distances on your car, first. The step of drawing Line "A" can be skipped if you can get the car nose right up to the wall and the lines located that way.

If this is your first time adjusting lights, it might be best to sketch out what you want to do before you leave your comfortable (and warm) abode. Spend some time locating the correct screws/hardware on your car, and see how the headlights move when the screws are turned one way then the other.

Adjusting the 2 high/low beam lamps (the outboard pair on a 4-headlight system) usually uses the same screws/hardware for both high and low beams. That is to say, you cannot adjust the high beam without messing up the low beam adjustment. Since the low beam is the more critical of the two, adjust the low beams and allow the high beams to go where they will (they’re usually pretty close). On a 4-headlight system, however, make certain the inboard high beams are adjusted properly.

Covers/protectors for the lights are a must. The 3M sticky stuff that's about 20 mils thick is a great protector against the small rocks and stones. Other covers work well, too, and should be used wherever possible - these lights are expensive. Check your local laws concerning headlight covers.

Check the condition of your headlight circuits. Check and clean the grounds, install relays if you have an older car or larger-than-usual wattage lights, check and clean all connectors, etc.

These instructions are for USA cars, those of you in RHD places will want to make the appropriate substitutions (gas = petrol, center = centre, tire = tyre, left = right, etc.).

Good driving!

Thomas Callahan