GM Service Manual Online
For 1990-2009 cars only

The charging system consists of the battery, the generator with built-in regulator, and the charging system indicator lamp circuitry. The generator supplies electrical power for charging the battery and operating the accessories.

The CS-130D generator features high ampere output per pound of weight. The CS stands for charging system and 130 is the measurement in millimeters of the outside diameter of the stator laminations.

This generator does not have a diode trio. The delta stator, rectifier bridge, and rotor with slip rings and brushes are electrically similar to other CS-series generators. A conventional pulley is used. Dual internal fans cool the slip rings, end frame, rectifier bridge and regulator.

The charge indicator, which appears on the instrument as a battery symbol, turns on when the ignition switch is closed and turns off when the engine is running. If the charge indicator is on with the engine running, a charging system problem is indicated. This will glow at full brilliance, not half lit, if any charging problem occurs or the system voltage is too high or too low.

Regulator voltage settings varies with temperature and limits system voltage by controlling rotor field current. It switches the rotor field current on and off at a fixed rate of about 400 cycles per second. By varying the on-off time, correct average field current for proper system voltage control is obtained. At high speed, the on-time may be 10 percent and the off-time 90 percent. At low speeds, with high electrical loads, on-off time may be 90 percent and 10 percent respectively.

The regulator has four terminals, P, L, I, and S. The P, I, and S terminals are not used. The L terminal provides an input to the instrument cluster for the charging indicator and voltmeter. For more information on the charging circuit, refer to Charging System Circuit Description .

The generator is serviceable by complete replacement only. No periodic maintenance is required. It should not be disassembled for any reason.