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.

Vehicle is equipped with the AD-237 generator. The AD-237 is similar to the earlier model CS-130D generator. See SPECIFICATIONS . The AD stands for Air-cooled Dual internal fans. The "2" is an electrical design designator, and the "37" denotes outside diameter of the stator laminations in millimeters. AD-237 generator major components include a delta stator, rectifier bridge, rotor with slip rings and brushes, regulator, dual internal fans and a conventional pulley. Generator is rated at 125 amps.

NOTE: The generator features permanently lubricated bearings. Service should only include tightening of mount components. Otherwise, replace the generator as a complete unit.

The generator uses only 2 wire connections and a ground path through the mounting bracket. The first wire connection is the BAT (output) terminal. This terminal supplies current to the battery and electrical systems through a fusible link. The second wire connection is the "L" terminal. This terminal is connected to PCM which monitors generator operation. Terminal "F" terminal is connected internally to the voltage regulator. The "S" terminal may be connected to an external voltage source, for voltage control.

Voltage regulator limits system 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 control correct average field current for proper system voltage. 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. The regulator grounds circuit 225 when charging system voltage is abnormal, and causes PCM to send a Class 2 message to Instrument Panel Cluster (IPC), which activates CHECK GAGES light.