4257: HP24 Switchback Turn Signal LED Bulbs Diode Dynamics

Upgrade. Add dual-color functionality and a modern appearance to your front turn signals with the 4257 HP24 turn signal bulb. Populated with sixteen amber chips and eight white chips, this bulb lights up white when your headlights are turned on, and flashes amber when the turn signals are activated. Housed in an aluminum casing for maximum heatsinking properties, the HP24 will last for years to come. Best of all, installation only takes minutes – simply take out your factory bulb and the HP24 will fit snugly in the socket.

The 4257 HP24 Switchback bulb features a custom-molded base connector, making it a true replacement for factory incandescent 4257-size front turn signal bulbs. Unlike a 3157 bulb that includes tabs on either side of the bulb, a 4257 bulb does not. The 4257 HP24 Switchback bulb is compatible with Ford vehicles using a dual-filament 4257-size front turn signal bulb with a clear reflector lens.

Switchback. Some Ford vehicles use a dual filament 4257-size front turn signal bulb, which allows you to add “switchback” functionality to your turn signal location. From the factory, the front turn signal lights up half-power amber when the headlights are on, and flashes full-power amber when the turn signal is activated.

By using this dual-filament design, along with the embedded digital timing circuit, you can upgrade this look: the HP24 lights up in a 6000K cool white color when your headlights are turned on, and flashes amber when the turn signal is activated. When you switch the turn signal off, it “switches back” to white. This allows you to upgrade your front end to an all cool white appearance,  while still keeping your turn signal functionality. The HP24 bulb is only suitable for vehicles that have a clear front turn signal reflector lens.

The 4257 HP24 Switchback bulb is compatible with Ford vehicles using a dual-filament 4257-size front turn signal bulb with a clear reflector lens. Unlike a 3157 bulb that includes tabs on either side of the bulb, a 4257 bulb does not.

Brightness. At 410 lumens, the HP24 will provide about double the total light output compared to your factory bulb. All Diode Dynamics LED lighting is rated with accurate, measured lumen figures, not calculations or guesses. We test the true output in-house, and provide you the real numbers to compare.

Reliability. Unlike other bulbs on the market, this bulb is built with constant-current circuitry, along with transient suppression. That means this bulb will last for years, not months, with no flickering or failure. And like every Diode Dynamics product, it’s backed by an industry-leading three-year replacement warranty.