Do I need to run new wiring, or does this use the factory harness?

The integrated switch mounts at the factory location. Confirm with your truck's existing switch cavity before ordering—some model years have blanks rather than pre-wired openings. If the cavity is blank, you'll need basic wiring to the battery and ground.

What bulbs does this kit use?

Bulb specification not included with this kit data. Check your vehicle's service manual or contact the parts counter with your truck's VIN for the correct bulb type and wattage.

Will these fit into the existing factory bumper openings?

These mount at factory fog light locations on second-gen Ram models. Test-fit before permanent installation to confirm alignment with your specific truck's bumper cutouts.