Headlight Assemblies Allow for Quick Changes

Headlight Assemblies Were Not Originally Allowed

In 1940, federal regulators standardized the headlights in American vehicles, requiring dual filament seven-inch sealed headlamps. This was referred to as a T-3 lamp. When the headlamp failed, the entire unit had to be replaced.

In 1957, the rules changed to allow two headlamps on each side—one for high beams and one for low beams. State legislatures had to change their statutes as automakers adopted that look.

Starting in 1975, smaller rectangular headlamps were approved. They could be either dual filament (one bulb on each side of the car) or two headlamps on each side. Despite these changes, headlamps were still all sealed glass, and when the headlight failed, the entire lamp had to be replaced.

In 1984 the regulations allowed for headlight assemblies. This meant that individual lamps could be replaced as needed. Automakers quickly started to incorporate headlight assemblies into new vehicles.

What Is a Headlight Assembly?

The four main components of a headlight assembly are:

• A housing that holds all the lighting fixtures, including the clear lens and optics or reflectors built into the unit
• A lamp that emits the low beam of light
• Another lamp for the high beam
• Turn signal bulbs

Headlight assembly – front and back

Usually, replacing a bulb is as simple as removing an electrical connector and twisting the bulb out from the back of the assembly. Then twist in a new lamp, attach the connector, and the headlight assembly is back in operation.

An owner can upgrade the lighting from the factory standard by swapping out bulbs. Before you do, check out this cautionary note.

Aftermarket vs. OEM

Original equipment manufacturer (OEM) assemblies typically are more expensive since they are offered by the automaker. When you buy an OEM unit, you can be assured that it will fit and is similar to the original. Aftermarket assemblies should have the exact fit and function, but often at a lower price. The assembly might have different materials than the OEM unit, and any optics and reflectors might not be as precise or accurately reproduced.

Can a Headlight Assembly Lens be Restored or Replaced?

Many headlight assemblies use a plastic lens. Over time, after being exposed to harsh UV rays, sand, and road debris, the lens can become yellow and cloudy. This could impede the lighting and be unsightly. There are numerous ways to clean the lens at an economical price.

Cleaning fogged headlights is a popular D-I-Y task.

If the lens develops a crack or the housing breaks, it is usually best to remove and replace the whole unit. If the lens is cracked, moisture eventually enters the unit and compromises the fixture. To remove an assembly, first disconnect all electrical connectors. Then remove the screws that hold the assembly in place. Once all the fasteners are removed, the entire unit should come out easily. Check your owner’s manual for complete details.

Related: Step-by-Step Instructions for Headlight Replacement

How Much Does a Headlight Assembly Cost?

A headlight assembly generally costs between $350 and $500 per fixture. Most vendors sell the replacement bulbs separately.

If you want to stick with stock, but are on a budget, consider a set of used headlight assemblies.

Headlight assemblies have seen significant styling change since first entering the market in 1985. eBay Motors has plenty of choices for you to consider when the need arises to replace a headlight assembly.