Diagnose dead headlights with our step-by-step troubleshooting guide. Learn to check fuses, bulbs, relays, and wiring—plus upgrade tips for reliable LED replacements.

Multimeter in hand, you can test resistance in circuit board components and appliance elements throughout the house.

Using a multimeter can be daunting to the uninitiated, but they're not magic. Here's a rundown of the basic functions of the device and what they're used for.