In most cases you will not, especially when your vehicle uses separate single-filament bulbs for both high and low beam. Vehicles using a single dual filament bulb (H13, 9003/H4, 9004, and 9007) for both high and low beam, we provide both bulbs with either dual-xenon bulbs or a xenon/halogen combination so you maintain full functionality. These do require a relay harness for installation (included in our kits) in order to properly connect the bulbs. We also offer single filament bulb versions where the dual functionality is not desired (high beams are operated by bolt-on lights, for example). Please contact our support team if you have questions regarding your installation.