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: Why headlights shouldn't be touched with fingers

He was telling you the truth. What happens is, are hands can be very oily without us noticing. When that oil gets on the bulb glass, those bulbs get super hot. Then that oil starts to burn to the higher...

Q: Headlights are really dim, car is brand new

The headlight system on your car is controlled by a module and this module will put out a low voltage to the headlights on low beam and maximum voltage on high beam. The lighting system is programmed in the module...

Q: Low beams not working. It is not a fuse.

Hello, Since you have covered the basics of checking fuses, I will assume that all the other lights illuminate including the high beams. Believe it or not, it is possible for both low beams to burn out at the same...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.