Sealed-beam headlights are common on older cars and they are the type of headlight where the bulb and the housing are one sealed unit. Composite lights are common on most newer cars where there is a sophisticated housing with a removable halogen or xenon bulb.
When performing a headlight replacement procedure, it’s a good idea to remove the old bulb or lamp and bring it with you to the auto-parts store to insure an exact replacement. It is also a good idea to replace both headlights at the same time. Also, as a safety precaution you should wear latex or similar gloves. Aside from keeping your hands clean, it will prevent oil from your hands from affecting the performance of the new bulbs. Oil or grease can greatly reduce the life of your new bulb.
Replacing a sealed-beam headlight is just slightly more complicated then replacing the bulb in a composite headlight. The first step is to locate and remove the retaining ring. You may have to remove a protective bezel or cover to locate the ring. This is a ring of metal which holds the headlight in place. Be careful not to confuse the screws of the retaining ring with the screws for the beam adjustment. Once the retaining ring is removed, slide out the headlight and remove the wiring harness from the back of the lamp and carefully remove the entire headlight. Attach the wiring harness to the new headlight and place it back in the headlight shell, insuring the embossed number or brand on the glass is upright and straight. Prior to reassembling the retainer ring is a good time to turn on the headlights and insure your new bulb is functioning properly. Reaffixing the retainer ring is performed in the opposite fashion of removing it.
Replacing a bulb in a composite system typically starts by first locating and removing the wiring harness attached to the rear of the headlamp assembly. Next, unlock the bulbs retainer by rotating it 1/8 of a turn, then gently pull back and remove it. Carefully remove the bulb itself by pulling it straight out. Insure the new bulb matches the old one and place the new bulb in the housing. NEVER touch the glass bulb itself, always handle the bulb from the base. You may have to rotate the bulb in either direction for the locating tabs to line up properly. Reaffix the retainer and insure it is locked in place. Reattach the wiring harness, turn on the headlights and insure your lights are functioning properly.
If after you perform the replacement procedure the lights still do not illuminate, insure you have fully seated the wiring harnesses. If this fails to rectify the problem, you may have to replace a fuse or there may be an electrical problem, in which case you should have the system inspected by a certified mechanic.