Saturn Coupes/Sedans/Wagons 1991-1998 Repair Guide

General Information


The battery and charging sub-system consists of a battery and an alternator with a built-in voltage regulator. The alternator is a lightweight, high performance component that provides electrical power for charging the battery and operating the accessories while the engine is running.

The alternator is constructed essentially of a rotor mounted on bearings in two end frames, a stator assembly, six silicon diodes, an internally mounted voltage regulator, and an integral fluid intrusion shield. The alternator develops AC voltages which are converted to DC current by way of a rectifier circuit.

The charging system also includes the Powertrain Control Module (PCM) software required to provide idle boost during low voltage conditions. The battery supplies current to the starter motor to crank the engine. After the engine starts, the charging system recharges the battery and supplies power to a variety of electrical devices in the vehicle. The PCM monitors battery voltage and will boost idle speed if the voltage drops below a calibrated amount.