Description & Operation

WARNING: This page is about a different car, the 2003 Oldsmobile Aurora and 2002 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.

WARNING: Vehicles are equipped with air bag supplemental restraint system. Before attempting any repairs involving steering column, instrument panel or related components, see AIR BAG DEACTIVATION PROCEDURES 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.

The AD237 generator has a high amperage output. The AD237 has an outside stator lamination diameter of 137 mm. Generators include a delta stator, rectifier bridge, and rotor with slip rings and brushes. A built-in regulator incorporates fault detection circuitry. A conventional pulley and dual internal fans are used to cool slip ring end frame, rectifier bridge and regulator.

The generator operates with 4 wire connections and a ground path through the mounting bracket. The first wire connection is the BAT (output) terminal. This terminal must be connected to the battery during operation. The second wire connection is connected from generator terminal "L" (connector terminal "B") internal regulator light driver to Powertrain Control Module (PCM). This circuit monitors and controls generator operation. The PCM controls indicator light function. The third wire connection is connected from generator terminal "F" (connector terminal "C") to PCM. The PCM also monitors this circuit. The fourth wire is connected from generator terminal "S" (connector terminal "D") to an external voltage reading. If this circuit is interrupted, regulator will default to internal voltage reading for control.

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. See GENERATOR SPECIFICATIONS .