The 2003 Nissan Xterra has 3,275 cc 3.3 liters V 6 front engine with 91.5 mm bore, 83 mm stroke, 8.9 compression ratio, overhead cam and two valves per cylinder VG33E which produced power: 134 kW, 180 HP SAE @ 4,800 rpm.
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. With the ignition switch in the Start position, power is supplied through ignition switch terminal ST to clutch interlock relay terminal 5. The starter motor plunger closes and provides a closed circuit between the battery and the starter motor. The starter motor is grounded to cylinder block. With power and ground supplied, the starter motor operates.
The Xterra generator provides DC voltage to operate the vehicle’s electrical system and to keep the battery charged. The voltage output is controlled by the IC regulator. Ground is supplied to combination meter terminal 43 through generator terminal L. With power and ground supplied, the charge warning lamp will illuminate. When the generator is providing sufficient voltage with the engine running, the ground is opened and the charge warning lamp will go off. If the charge warning lamp illuminates with the engine running, a fault is indicated.
Find more information about 2003 Nissan Xterra Starting and Charging System Service Data and Specification, Battery, Generator, Fusible, Fusible Link and Electrical Units here. (source: bebrs.pie-dabas.net)
Find also other interesting Nissan Wiring Diagram here.