This was a special project developed for a customer. The request was to have an H4 bulb use low beam while in high beam mode. So, we made it possible for an H4 (9003) halogen bulb to stay on low beam while the high beam is activated by using 2 directional diodes. The diodes prevent current flow from low to high and high to low wires in the car’s system but will send power to the bulb if placed between the high and low wires and on the low wire. This setup may not work for LED bulbs designed to use only one setting at a time (ie. low beam or high beam).
PARTS USED:
No Warranty
