Bulbs

Frequently Asked Questions About Bulbs

How do I know which bulb size and type fits my truck?

Bulbs are identified by a standardized bulb number or trade number, such as 194, 1157, 3157, or 921, which refers to the base style, size, and wattage rather than the make or model of your truck. Check your existing bulb for a number stamped on the metal base, or refer to your truck's owner manual to confirm the correct bulb number before ordering.

What is the difference between standard, LED, and halogen bulbs?

Standard incandescent bulbs use a filament and are the most affordable option, halogen bulbs use a filament inside a halogen gas capsule for a brighter, whiter light, and LED bulbs use solid state diodes that run cooler, draw less power, and typically last significantly longer than either filament-based option. Each type is available in many of the same bulb numbers, so you can often upgrade without changing your truck's wiring or housings.

Will LED bulbs work in all of my truck's light housings?

In most cases LED bulbs will physically fit and function in housings designed for incandescent or halogen bulbs of the same bulb number, but some vehicles use circuitry that can cause LED bulbs to flicker, flash a warning, or hyper-flash in turn signal applications. If you notice unusual behavior after installing LED bulbs, a load resistor or an LED-specific flasher relay can usually resolve the issue.

How long should a bulb last, and why did mine burn out early?

Lifespan varies widely by bulb type and application, with LED bulbs generally lasting the longest and standard incandescent bulbs the shortest, but constant vibration, moisture intrusion into a housing, or a wiring issue causing voltage spikes can cause any bulb to fail prematurely. If you are replacing the same bulb repeatedly, it is worth inspecting the socket, wiring, and housing seal in addition to the bulb itself.

Are these bulbs legal for on-road use and DOT compliant?

Most bulbs sold for exterior lighting, such as headlights, brake lights, turn signals, and marker lights, are manufactured to meet applicable DOT and SAE requirements for color, brightness, and beam pattern. That said, regulations can vary by state, so always confirm that the bulb type and color you select is appropriate for the specific light fixture and legal for use on public roads in your area.