For Halogen Headlights (most common):
1. Park your car on a level surface: This is crucial for accurate adjustment. About 25 feet away from a flat wall is ideal.
2. Turn on your headlights: You need to see the beam pattern.
3. Locate the adjustment screws: These are usually located on the back of the headlight housing. You may need to remove the access panel or cover to reach them. This access panel is often in the engine bay, requiring some maneuvering. A flashlight will be helpful. The screws are typically vertical and horizontal, controlling up/down and left/right adjustments, respectively. They often have a small plastic cap that you'll have to carefully remove, or they may be plainly visible. Consult your owner's manual if you're having trouble locating them.
4. Identify the adjustment screws: They're usually marked with symbols indicating up/down and left/right adjustments.
5. Adjust the headlights: Use a small flathead screwdriver to carefully turn the screws. Small adjustments are key. Turn the vertical screw to raise or lower the beam. Turn the horizontal screw to adjust the left/right aim.
6. Check the beam pattern: After each adjustment, check the beam pattern on the wall to ensure it's aligned correctly. The ideal setup is to have the beam's cutoff point slightly below the horizontal center.
7. Repeat steps 5 & 6: until the headlights are properly aimed. The aim should be such that oncoming drivers aren't blinded, yet you have optimal illumination down the road.
Important Considerations:
* Owner's Manual: The best place to find precise instructions and diagrams is your 2002 Chevy Impala owner's manual.
* Professional Adjustment: If you're uncomfortable working on your car's headlights, it's best to take it to a professional mechanic or auto repair shop. They have the tools and expertise to make sure the adjustment is done correctly and safely.
* Xenon/HID Headlights: If your Impala has HID headlights, the adjustment procedure is often more complex and might require specialized tools or software to access the electronic control modules. Do not attempt to adjust these yourself unless you have the proper equipment and knowledge.
* Safety: Always work in a well-lit area and be cautious when working near the headlights and engine components.
Remember, improperly aimed headlights can be dangerous, both for you and other drivers. If you are unsure about any step, it's always best to seek professional help.
