How to Ground Headlights

A headlight is normally grounded to the chassis of a vehicle in order to allow electricity to complete a circuit and return to the vehicle's negative battery terminal. If the headlight's ground loosens or disconnects, the headlight will begin to blink, dim or go out completely.


Although vehicle headlights can vary drastically in look they all ground to the vehicle in the same way. Some knowledge of wiring is important to anyone trying to complete this task.

Things You'll Need

  • Multimeter
  • Self-tapping screw
  • Screwdriver
  • Wire cutters (optional)
  • Park the vehicle on a flat surface and set the parking brake. Open the hood and secure it in place with the hood prop. Disconnect the negative battery cable.

  • Unplug the wiring harness from the rear of the headlight. Trace the route of each of the wires coming from the wiring harness until the ground is found. The ground is the wire that runs directly to the chassis. If it has broken off of the chassis, it will be hanging free at the far end.

  • Start screwing a self-tapping screw into the vehicle chassis. Wrap the end of the ground wire firmly around the screw, then tighten the screw until the head pins the wire to the chassis.

  • If the end of the wire is damaged or no wire is showing, clip off an inch of the ground wire with wire cutters. Strip one and a half inches of insulation from the end of the wire and expose enough of the ground to wrap around the screw.