BackOFF™ XP Brake Light Module - Signal Dynamics To install, wire the BackOFF™ XP Brake Light Module in-line with your existing brake light wire. Locate your brake light wire and cut the wire into 2 (use a test light or multi-meter to find proper wire). SDC Back-Off XP Brake Light Signal Module Installation On Royal Enfield Bullet Motorcycle BackOFF-XP Signal Dynamics Back Off XP Brake5/5(63)[PDF] Light Wiring Tutorial - JcrOffroad is no override to keep the aftermarket lights off at all times. Finding a place to tap into the factory backup lights in the cab or in the PDC and keeping the relay under the hood in this instance can help make these wire runs shorter. The diodes These are used to keep power from the switch or factory backup lamps from back feeding each other.