How does high/low work?

High beam/Low beam function is specific to 4-headlamp or 2-headlamp systems.

Dapper Lighting’s 2-Headlight systems all use solenoid controlled High/Low projectors. Unlike 4-headlamp systems that have a separate housings designed for both high beam AND low beam, 2-headlamp systems must provide “Bi-Xenon”.

Bi-xenon, simply defined, means each projector is capable of both low and high beam patterns. In Dapper Lighting headlamps, the cutoff shield within the projector is on a hinge. When powered by a signal taken directly from your OEM high beam switch, the solenoid pulls or pushes this shield down (depending on the design). This releases and exposes more light through the projector lens thus creating the high beam pattern. Conversely, when the high beam is turned off, the solenoid retracts the cutoff shield to its normal low beam position.

 This design is especially useful with HIDs. Xenon/HIDs are not very suitable as separate high beams, since they have a longer warm up and cool down time and flashing them drastically reduces their lifespan. Bi-xenon, also known as solenoid-type projector systems, avoid this problem.

 For 4-headlight systems Dapper Lighting currently uses 2 types of projectors, Low beam cutoff shield and High beam which has no cutoff shield.

A third type, which Dapper Lighting is currently working on for 4-Light systems, uses the Bi-Xenon projector that is similar to the ones in the 2-headlight systems. This projector also allows for a single cutoff shield, which is on a hinge, that can provide low beam or high beam. Many OEM systems use this design, and you’ll often hear them described as Bi-Xenon or Bi-function lights.

Have more questions? We'd be happy to help. Either send an email to or call us at (415) 493-8236