A retrofit replaces or upgrades an existing light while retaining much of the original vehicle or installation. An LED retrofit must match the electrical system, connector, mounting, space, light pattern, and required approvals; similar dimensions or higher lumens alone do not ensure a suitable replacement. The replacement should deliver the correct illumination for the operator rather than simply reproduce the old lamp’s appearance. Installers should check voltage range, current draw, EMC, environmental ratings, bracket strength, cable and connector condition, clearance, thermal environment, and any road-use approval. A photometric comparison helps confirm that coverage and glare remain acceptable.