The Isuzu Reach high beam and low beam headlight bulbs both utilize a 9003 bulb size. The replacement chart covers vehicle production spanning 2011 to 2013.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Isuzu Reach uses the 9003 bulb type across all listed model years (2011-2013) for both high beam and low beam headlight positions.
The 9003 is an ANSI-standardized bulb designation used in the United States and Canada, distinguishing it from region-specific equivalents sold under different part numbers in other markets.
As a dual-filament halogen bulb, the 9003 contains two separate tungsten filaments within a single housing, one rated at 60 watts for high beam output and one at 55 watts for low beam output.
The 9003 uses a P43t base, which is a bayonet-style mount with a 43mm flange, and this base type determines physical fitment into the headlight housing.
The bulb operates on a 12-volt electrical system, consistent with standard automotive electrical architecture.
Because the same 9003 bulb specification applies to both the high beam and low beam positions on the Isuzu Reach, a single bulb type serves both functions rather than requiring two separate part numbers.
The 9003 and H4 bulbs share the same dual-filament halogen design and P43t base, making them functionally interchangeable in many applications, though fitment should be confirmed against the specific housing before substitution.