How to Replace a Headlight Bulb

Turn the headlights on with the car parked. Walk around to the front and check both sides. Sometimes only the low beam is dead and the high beam still works, so flick the high beams on too and watch for the bulb that stays dark.

Once you know which one is out, grab the owner's manual. There's a section for headlamp bulb replacement that lists the exact bulb code your car takes (something like 9007, H11, or 9005). If you don't have the manual, the auto parts store can look it up by year, make, and model.

Pop the hood and prop it open. The headlight assembly sits at the very front corner of the engine bay, and the bulb screws into the back of it.

Reach behind the assembly and feel for the round housing where a wire harness plugs in. That's your target. On some cars you have great access from above. On others you'll need to come at it from underneath the front bumper or from the wheel well. The owner's manual diagram will tell you which.

Most halogen bulbs are held in by a thin metal spring clip that pivots over the back of the bulb. Squeeze it toward the bulb to release the tension, then swing it up and out of the way.

Pay attention to how it sits before you pop it. Snap a quick phone photo if you need to. You'll be reversing this exact motion to lock the new bulb in.

With the clip released, pull the old bulb straight out of the housing. Hold it up to the light and look at the two thin coiled filaments inside the glass. One is the high beam, the other is the low beam.

A working filament looks like a clean, intact spring. A blown one will be broken, sagging, or visibly burned through. Confirming this before you install the new bulb tells you the bulb really was the problem and not a fuse or relay.

Put on a pair of nitrile gloves before you open the new bulb. Skin oil left on a halogen bulb creates a hot spot that shortens its life and can crack the glass when it heats up.

Hold the new bulb only by the plastic base. Line up the tabs with the slots in the housing and slide it straight in. There's only one orientation that fits, so if it doesn't seat flush, rotate it and try again.

Swing the spring clip back over the base of the new bulb and push it forward until it snaps into place. It should feel firm, not floppy. If the bulb wiggles, the clip didn't seat correctly - reseat it and try again.

Plug the wire harness back into the connector on the bulb base. Most clip on with a satisfying click. Give the harness a gentle tug to make sure it's locked in.

Hop in the car, turn the key to accessory, and switch the headlights on. Walk around to the front and confirm the new bulb is shining at the same brightness as the other side. Try the high beams too.

If everything looks even, do the other side now while you're already set up. Headlight bulbs age together, and a fresh bulb next to a dim three-year-old one looks lopsided at night. Twenty minutes of work saves a second driveway session in two months.