Description & Operation

WARNING: Vehicles are equipped with air bag supplemental restraint system. Before attempting any repairs involving steering column, instrument panel or related components, see DISABLING & ACTIVATING AIR BAG SYSTEM in AIR BAG RESTRAINT SYSTEMS article in RESTRAINTS.

CAUTION: When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery.

CS 130D (Charging System) series generator is rated at 100-amp output. See GENERATOR SPECIFICATIONS . The "130" designation is outside diameter of stator laminations, measured in millimeters. CS series generators include a delta stator, rectifier bridge, voltage regulator, dual internal cooling fans, and rotor with slip rings and brushes. A built-in regulator incorporates fault detection circuitry. See Fig 1.

Generator operates with 2 wire connections and a ground path through mounting bracket. First wire connection is BAT output terminal. This terminal must be connected to battery during operation. Second wire connection is connected from generator internal regulator lamp driver to Powertrain Control Module (PCM) or Vehicle Control Module (VCM). This circuit monitors and controls generator operation.

Regulated voltage varies with temperature. System limits voltage by controlling rotor field current while field current is on. Regulator switches rotor field current on and off at a fixed frequency of 400 cycles per second to help control radio noise. By varying overall on/off time, correct average field current for proper system voltage control is obtained. At high speeds, with lower electrical loads, on-time may be 10 percent. At low speeds, with higher electrical loads, on-time may be as much as 90 percent.

Fig 1: Typical Charging System Wiring Schematic (CS 130D Series)

Courtesy of GENERAL MOTORS CORP.