A Guide About 9003 Headlight Bulb

A double-filament headlight bulb is the 9003 headlight bulb. Instead of having two separate bulbs, they can be used as high and low beams. Some automobiles also have fog lights that utilize 9003 bulbs. These lights are also common on many motorcycles. By opening the engine compartment and removing the headlight assembly from the inside, you can get to your car’s headlight bulbs. The fog light is located underneath the headlight assembly.

The old bulb needs to be taken out and the new one connected. It’s crucial to carefully assemble the new bulb so that the tabs connect to the appropriate wiring. Three wires are used in 9003 bulb-compatible sockets. A red wire powers the high beam filament, a yellow wire powers the low beam, and a black wire serves as the ground.

The ground tap should be on the right, the high beam tab should be on the left, and the low beam tab should be on top of a normal socket. However, different socket configurations can be found. To determine what kind of socket you have and how to correctly wire your new bulb, carefully look at the headlight bulb. Because they have a double filament and three tabs or prongs that emerge from a straight base, 9003 bulbs are simple to identify.

How to Pick the Correct Car Headlight Bulb?

You must ascertain whether your car needs single or dual filament bulbs. There are models of H7, H11, 9005, and 9006 single filament bulbs. You will probably need a 9003, H4, H13, 9004, or 9007 bulb if your car has dual beams.

Additionally, the replacement bulb needs to fit the socket in your car. While some bulbs’ bases are L-shaped, others fit directly into the socket. To decide which bulbs will fit, pay attention to the socket’s position and angle.

Checking your owner’s manual or researching what kind of bulb your car requires online are the best places to start when looking for a replacement. It should be simple to locate a model number.

9003 Headlight Bulb Guide - How is it different than H4? - My Car Makes  Noise

But bear in mind that some bulbs can be switched out. For example, the H4, 9003, and HB2 bulbs are very similar. A car that can use 9004 bulbs will also work with 9007 versions. HB4 bulbs can typically be substituted for 9006 bulbs.

Installing a 9003 Headlight Bulb

A 9003 headlight bulb is simple to install. Following are some pointers to bear in mind:

  • Keep in mind that the engine compartment is where you should access the headlamp assembly and not the outside.
  • When handling the bulb, use caution. Oils from your fingers will collect on the bulb if you touch it, and when it heats up, it could cause harm.
  • Properly place the headlight bulb. The beam pattern won’t look right if it’s upside-down or crooked.
  • You can buy an adapter to make the replacement bulb fit the socket if it doesn’t fit properly without one.


To ensure the greatest fit, it’s ideal to get the bulb model that the maker of your car suggests, but if that’s not an option, a suitable bulb will work. You can shop here to explore the variety.