His harness fixes:dim headlights Back feeding power Flickering headlights Malfunctioning headlights when using hi/low beams Overloading the headlight switch Overheating plugs This is a h 4/9003 12v headlight conversion wiring harness with hi heatceramic plugs for cars that have upgraded halogen or xenon h 4 bulbs.H4 2 headlight harness for headlight interchange:h 4 conversions h 6024 headlights The stock headlight switch cannot handle the necessary power needed to light the hi watt halogen bulbs so headlights overload the headlight switch & end up making the lights dim, flicker, or turn off. this harness bypasses the power draw from the headlight switch & pulls the power directly from the cars battery, but still uses the stock headlight switch to activate the relays to turn the headlights on & 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 & plug with all the correct factory style plugs for the high & low beam headlights! Package included:1x h 4 relay harness