REMOVAL & INSTALLATION
If some or all of the headlight bulbs being replaced still operate, refer to the headlight aiming procedure later in this section to ease checking or adjustment of the headlights after installation.
- Disconnect the negative battery cable.
- Loosen and remove the retaining screws, then remove the headlight bezel from the front of the vehicle.
- On most models, the headlight bulb retaining ring is only held on by retaining screws. If so, remove the bulb retaining ring screws. These are the screws which hold the thin metal ring which holds the bulb against the adjusting plate. Do not touch the two headlight aiming screws, at the center of the top and side of the retaining ring (these screws will have different heads), or the headlight aim will have to be re-adjusted.
One way to identify the retaining ring screws is that they will be threaded through a lip on the outer edge of the retaining ring before threading through the adjusting plate. One the other hand, the adjustment screws are first threaded through the adjustment plate and then a spring loaded holder underneath it.
- Some later model vehicles may use a spring on the retaining ring. If so equipped, disengage the spring from the retaining ring, using a cotter pin removal tool, then remove the retaining ring screws.
- Pull the bulb and ring forward and then separate them. Unplug the electrical connector from the rear of the bulb and remove the bulb from the vehicle.
- Plug the new bulb into the electrical connector.
- Position the retaining ring over the bulb, then install the assembly to the adjusting plate. Secure using the retaining screws and, if applicable, the spring.
- Install and secure the headlight bezel.
- Connect the negative battery cable.
The headlights must be properly aimed to provide the best, safest road illumination. The lights should be checked for proper aim and adjusted as necessary. Certain state and local authorities have requirements for headlight aiming; these should be checked before adjustment is made.
Headlight adjustment may be temporarily made using a wall, as described below, or on the rear of another vehicle. When adjusted, the lights should not glare in oncoming cars windshields, nor should they illuminate the passenger compartment of cars driving in front of you. These adjustments are rough and should always be fine-tuned by a repair shop which is equipped with headlight aiming tools. Improper adjustments may be both dangerous and illegal.
For most Chevrolet vehicles, horizontal and vertical aiming of each sealed beam unit is provided by two adjusting screws which move the retaining ring and adjusting plate against the body of the coil spring. There is no adjustment for focus; this is done during headlight manufacturing.
Before removing the headlight bulb or disturbing the headlamp in any way, note the current settings in order to make adjusting the headlights upon reassembly easier. If the high or low beam setting of the old lamp still works, this can be done using the wall of a garage or a building:
- Park the car on a level surface, with the fuel tank no more than 1 / 2 full and with the vehicle empty of all extra cargo (unless normally carried). The vehicle should be facing a wall which is no less the 6 feet high and 12 feet wide. The front of the vehicle should be about 25 feet from the wall.
The car's fuel tank should be about half full when adjusting the headlights. Tires should be properly inflated, and if a heavy load is normally carried in the trunk or in the cargo area of station wagons, it should remain there.
- If this is be performed outdoors, it is advisable to wait until dusk in order to properly see the headlight beams on the wall. If done in a garage, darken the area around the wall as much as possible by closing shades or hanging cloth over the windows.
- Turn the headlights ON and mark the wall at the center of each light's low beam, then switch on the brights and mark the center of each light's high beam. A short length of masking tape which is visible from the front of the car may be used. Although marking all 4 positions is advisable, marking 1 position from each light should be sufficient.
- If neither beam on 1 side of the vehicle is working, park another like-sized car in the exact spot where the Chevy was and mark the beams using the same side light on that car. Then switch the cars so the Chevy is back in the original spot. The Chevy must be parked no closer to or farther away from the wall than the second vehicle.
- Perform the necessary repairs, but make sure the car is not moved or is returned to the exact spot from which the lights were marked. Turn the headlights ON and adjust the beams to match the marks on the wall.
- Have the headlight adjustment checked as soon as possible by a reputable repair shop.