How to Connect Fog Lights to a Battery

Fog lights are a very common add-on aftermarket accessory, especially if you travel in bad weather or at night often. Fog lights illuminate the area directly in front of your vehicle, filling in the gap left by your vehicle's regular low-beam headlights. Fog lamp kits are available in auto parts and discount stores and come with directions. When it comes time to wire power to your fog lamps, most directions advise you to connect to the positive lead on your vehicle's battery without going into great detail. Knowing how to correctly connect your fog lamps to your vehicle's battery creates a professional-looking installation.

Things You'll Need

  • Wire stripper
  • Fuse holder tap
  • Pliers
  • Continuity tester
  • Fuse puller
  • Fog lamp fuse
  • Locate your vehicle's fuse box under the dashboard on the driver's side of the vehicle or under the hood near the firewall. Remove the cover of the fuse box, and set it aside.

  • Strip ¼ inch of insulation off the end of the power wire for your fog lamps using a wire stripper. Open the jaws of the stripper, and place it over the end of the wire ¼ inch from the end. Squeeze the handle together, and slide the stripper towards the end of the wire to remove the insulation.

  • Insert the fog lamp power wire that has been stripped into the end of the butt connector on a fuse holder tap. Crimp the end of the butt connector down onto the wire with a pair of pliers so that the wire cannot be pulled out.

  • Use a continuity tester to find an existing fuse in your fuse box that has current. Connect the squeeze clip on the tester to bare metal, such as the frame work under your dashboard, to ground the tester. Push the metal tip of the tester into the contacts of each fuse until the handle on the tester lights up, indicating current. Make sure the fuse you have chosen has enough amperage to handle your fog lights. Check the directions that came with your fog lights to determine the amperage of your lights.

  • Remove the fuse you have chosen from the fuse box with a fuse puller. Push the protruding connectors on the fuse holder tap into the fuse box in place a of the fuse you just removed. Push the fuse your removed into the first position on the fuse holder tap so that the original circuit will still operate.

  • Push a fuse with an amperage recommended by your fog lamp manufacturer into the second slot on the fuse holder tap. Replace the cover on the fuse box.