The right headlight was not working on this 2003 Nissan Altima. The customer had tried to change the bulb and had caused some minor body damage and his wife said no more take it to the shop. Changing the headlight bulbs on these cars is not easy by design. You see if you have HID or Xenon bulbs they operate off of very high voltage and the voltage can kill you so the manufacturers would prefer that untrained personnel would not attempt to change the bulbs. You of course can do it safely but use caution. The main thing is to not backprobe any wire in the system and DO NOT TOUCH the actual wiring at the bulb with the HID module plugged in. Not all of these cars use the Xenon bulbs for the low beam, some just use a regular halogen bulb. This is what you have to do to change the bulb in either system.
You start by removing the filler cover over the top of the radiator and the front facia. There are several push pin type fasteners that hold it in place. Sorry for the lack of a picture. Next you can remove the two visible bolts for the headlight housing.
Next remove the clips that hold the lower filler panel to the front facia and several around the wheel well openings.
Once the fasteners have been removed from the wheel well opening enough to flex them back, locate the two screws inside that hold the horizontal edge of the front facia to the lower edge of the fender. The picture shows the one closest to the the wheel but there is another one several inches in that also has to be removed. Repeat the process for the other side.
Start sliding the facia off the car but be sure to support it enough to remove the fog light wiring connectors. An extra person to help is convenient but not necessary.
Now you can remove the hidden screw. The module below the headlight bolt with the yellow warning label is the one to respect.
If you need to disconnect the harness connector from the HID control Unit for testing make sure the key is off, the lights are off and preferably disconnect the battery following manufacturers instructions. DO NOT try to test the wiring with the unit hooked up, you could die or be seriously injured. The testing of the wires should be as follows. Low beam power input to the red/yellow wire, ground input on the black wire and continuity between the remaining wires at the HID module connector and the contacts at the bulb connector. Below is a side view of the area showing the yellow warning sleeve on the wiring and the last screw to remove in order to pull the headlight assembly from the car.
With the proper safety precautions taken remove the gray plastic housing from the rear of the assembly. It twists off.
Now you are finally at the low beam bulb. Another warning label not to die!!!
Pull the harness connector off of the bulb. Release the two ears of the spring clip that holds the bulb in place. Remove the old bulb and install the new. Be very careful not to touch the glass as dirt and body oil from your fingers will cause the bulb to blow and the bulb costs about $100 +-.
Reconnect the harness to the bulb. Install the gray cover, bolt the headlight in place and test the function. Because of the labor involved I recommend changing all of the bulbs while you have it apart. The choice is yours.
And we have light!!!
Put the front of the car back together and the job is done.