A multimode controller for LED light sources, especially sources in warning lights, such as light bars, provides for a temporary increase in brightness from the LEDs by providing a burst mode, in addition to a flashing mode and a continuous mode. The modes are carried out by programming a microprocessor which receives signals from control switches, which may be pressed and released. The programming precludes the burst mode to continue for longer than a predetermined time thereby ensuring that the power does not exceed the LEDs damage threshold characteristic. The controller thereby provides for temporary bursting to make visible the region in front of or around an emergency vehicle for a short period of time without the need for light sources dedicated solely to the high intensity brightness mode of operation of a warning light system.