The 2004 Subaru Outback typically uses an H4/9003 dual-filament headlight bulb. This is the standard for the model’s traditional reflector headlights in most North American-spec vehicles.
This article explains the common bulb type for the 2004 Outback, how to verify which bulb your specific car requires, and what to expect if your headlights have been swapped to an aftermarket or European-style assembly.
Typical bulb type for the 2004 Outback
Most 2004 Outback models with the original headlight housing use a single bulb that provides both low and high beams. In North American specifications, this is commonly the H4 (9003) dual-filament bulb.
Common configurations by market or aftermarket
Because headlight assemblies can vary by market, model year, or aftermarket replacements, some Outbacks may not use the exact same bulb as the stock North American version.
Common options you might encounter:
- H4 (9003) – dual-filament bulb, standard for many 2004 Outbacks with factory-type reflectors.
- Variants with separate high/low bulbs in non-U.S. or aftermarket housings (for example, configurations that use distinct low-beam and high-beam bulbs). These are less common for original equipment on 2004 North American Outbacks and typically require different headlight assemblies and wiring.
To confirm your exact bulb, inspect the current bulb by removing the dust cap or refer to the owner’s manual or a parts diagram for your VIN. If in doubt, bring the existing bulb to a parts retailer for an exact match.
How to identify the correct bulb for your car
Begin with the easiest method: check the bulb currently installed in the headlight housing. If your vehicle uses a single dual-filament bulb, you’re likely dealing with H4/9003. If you have two separate bulbs (one for low beam and one for high beam), your setup is different from the traditional H4 arrangement.
If you’re purchasing replacements, consider the following steps:
- Open the hood and locate the headlight assembly.
- Remove the dust cap and gently unplug the wiring harness to examine the bulb base.
- Match the base shape and markings (for example, “H4” or “9003”) to purchase the correct replacement.
When in doubt, consult the owner’s manual or contact a Subaru parts specialist with your VIN to ensure you get the exact bulb type for your vehicle.
Summary
For most 2004 Subaru Outback models, the standard headlight bulb is H4/9003, a dual-filament bulb that handles both low and high beams in one unit. Verify your exact setup by inspecting the bulb or consulting the vehicle’s documentation, especially if your headlights have been replaced with aftermarket or non-U.S. assemblies. When purchasing replacements, bring the old bulb or reference your VIN to ensure an exact match.