The following article discuss the 2003 Nissan Xterra starting and charging system. Nissan Xterra power is supplied at all times through 40A fusible link to ignition switch terminal B. The Xterra generator provides DC voltage to operate the vehicle’s electrical system and to keep the battery charged. 2003 Nissan Xterra Starting and Charging System Service Data and Specification, Battery, Generator, Fusible, Fusible Link and Electrical Units here.