Q: Are High and Low Beams Separate Bulbs?

asked by on

Are high and low beams separate bulbs?

This is a great question since depending on the vehicle and manufacturer the lights can be configured in different ways. This can be a concern if you find your headlights are not working, since you need to know what type of bulbs to but to replace them with properly. Since the lens in modern headlights is separate from the bulbs this present a problem when replacing a lens for damage such as discoloration or from an impact.

Cars are built using single or dual filament bulbs. Older cars with single lights had dual filament bulbs that housed both the low beam and high beam light elements in a single bulb housing. These vehicles had two headlights total on the front one on each side. Then the design moved to individual bulbs which were single filament elements with a specific purpose of either a low or high beam light. These bulbs were arranged four total to the front of the car and configured either side by side on one on top of the other. The element in these bulbs work in a similar fashion to a household incandescent bulb. You may be even wondering how headlights work in general.

The adjust of the main beam of light from each of these light types is aimed or directed at different angles to improve the distance and angle of light beam reflected onto the road ahead of a vehicle. If the vehicle has a single headlight bulb (not the lens or reflector, but the actual bulb) then the bulb will have a dual filament internally which, when provided with battery power, will cause electrical current to flow through the element similar to the heating grid in an electric oven or a hair dryer. In the case of the bulb, it will cause it to glow.

In a separate light system where the low and high beam units are separate bulbs, each has only one filament and will illuminate when power is applied. Modern vehicles us one or more bulbs housed in a reflector assembly that appears to be one headlight unit. Keep in mind that there are also high intensity lights and LED lights as well used in these applications.

A concern that is often noted as well is when the headlight appears dimmer than the other, as if the dim light were about to blow out. So get your lights checked, replaced, and adjusted to see what’s on the road ahead.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Are High and Low Beams Separate Bulbs?

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Q: Brake lights don't work

Hello. This is typically caused by a brake light switch problem. This is located on the brake pedal assembly and is a common failure. I always test them before replacing them, but most of the time these are bad and...

Q: Driving lights not working

You may have a pair of blown out headlights. I have seen this a lot with Hyundais for some reason. There is a possibility that there may be another electrical problem as well. I would ask for help from one...

Q: Xenon low beam not working

Hello. There is likely an electrical fault on the vehicle side of the wiring harness. Blow fuses or broken wires can plague any electrical system. I recommend having an experienced technician inspect the circuitry concerning the vehicle exterior lighting system....

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...