Capacitors are used after LED or HID upgrade where the bulbs flicker or strobe but DO NOT shut off after the vehicle is started. The capacitors absorb voltage variations and release a steady stream of power to your LED or HID bulbs, making them perform as intended. If your headlights strobe briefly and then shut off, please try using the canbus anti-flicker modules first, and if they don't resolve the shutting off issue, add resistors.