In this article, we will outline the best 9003 HID kit installation instructions and show you a before and after shot of the headlights. H4 is the same bulb as the 9003, so don’t be confused if you see an H4 on a new headlight bulb package or HID kit.
Let’s start from the reason why we are going to spend the next half hour of installation:
No comments required.
2 wires connect the bulb to the Ballast and there is a 1-way connection to each wire that makes no chance to wire it another way.
After connecting the Ballast to the bulb we need to hook up the beam selection wire and the Ballast to the Relay harness.
These bolts may be located in random places around each headlight, just check for them.
Connect the relay harness to the battery (the Red wire with the Fuse):
Carefully tighten all the wiring that may hang, to prevent any possibility of wire coating damage:
Now it is time to go through all the wiring and check connections:
– The bulb is connected to ballast with 2 wires
– Bulb (high and low beam) is connected the relay harness with 1 wire
– Ballast is connected the Relay harness
– Relay harness has a grounding on each side, it is really important to ground the kit properly on both sides
– Relay harness is hooked up to the Positive connection of Battery with the Red wire
– Relay harness is connected to the car female socket that used to go to the bulb (3 wires connector)
Now that we checked everything it is high time to turn on the upgraded headlights: