Rock lights

Also called rock crawling lights, wheel well lights, undercarriage lights

Rock lights are small lights bolted into the wheel wells or under the frame rails and aimed down, so a driver and a spotter can both see exactly where the tires, rocker panels and skid plates sit relative to the obstacle in front of them after dark.

What are rock lights for?

Baja Designs names this Zone 6 in its lighting system and describes it plainly: lights designed to illuminate wheel wells and the undercarriage, ideal for navigating tight situations, providing visibility under and around the bottom of the vehicle. That is the whole job. A rock light is not there to help you see the trail ahead. It is there to help you see the eight inches around each tire while you place it.

Typical placement is one light per corner, inside the wheel well or on a rock slider or bumper, and Baja Designs' own guidance calls for no more than that in most cases, with dedicated rock crawlers sometimes adding more. Some builders also run one inside a roll cage or on the tailgate, less for wheel placement than for camp use and trail repairs after dark.

Not the same thing as underglow

Decorative underglow lighting, RGB strips run for looks, uses the same wheel-well real estate and gets confused with rock lights constantly, but the two are built for different jobs. A rock light is white or amber, aimed to spill light on a specific, useful patch of ground: the gap between a rocker panel and a boulder, the clearance under a skid plate, exactly where a tire is about to land. Color-cycling underglow is not aimed at anything in particular and is not meant to be.

A second job at camp

Aimed down and mounted low, rock lights double as work lighting under the vehicle at camp: checking for a leak, swapping a shock, finding a dropped bolt. It is a minor benefit next to their trail job, but it is real, and it is one more reason they tend to be wired to their own switch rather than tied to the headlights.