This is a H4/9003 12v headlight conversion wiring harness with hi-heat ceramic plugs for cars that have upgraded halogen, LED or Xenon HID H4 bulbs. The stock headlight switch cannot handle the necessary power needed to light the hi watt halogen bulbs so headlights overload the headlight switch and end up making the lights dim, flicker, or turn off. this harness bypasses the power draw from the headlight switch and pulls the power directly from the cars battery, but still uses the stock headlight switch to activate the relays to turn the headlights on and off. The ceramic plugs wont melt like standard plastic plugs will from the higher heat that halogen bulbs put out. this is harness is a direct plug and play with all the correct factory style plugs for the high and low beam headlights! manufacturer cross reference h4 2 headlight harness for headlight interchange h4 conversions h6054 headlights 6052 headlights