Skylark V6-3100 3.1L VIN M SFI (1996)
DESCRIPTION
The CS alternator is available in three sizes: CS-121, CS-130, CS-130D and CS-144. The numerals denote the outer diameter of the stator laminations
in millimeters and the letters CS stand for charging system. The CS-144 can be serviced. The CS-121 and CS-130 series are serviced as an assembly
only.
The CS alternators, Fig. 1 and 2 , use a new type regulator and a diode trio is not used. A delta stator, rectifier bridge, and rotor with slip rings and
brushes are electrically similar to earlier alternators. A conventional fan mounted next to the pulley pulls air through the assembly for cooling. An
internal fan mounted on the rotor pulls air through the slip ring end frame to cool rectifier, bridge and regulator. Air is expelled through openings in
the end frame. No periodic maintenance is required.
OPERATION
CS-130 and CS-144 alternators may be used with only two connections. The battery positive BAT terminal must be connected to a battery during
operation. The second required connection is through the indicator light, or a suitable external resistor to L terminal of the regulator which serves to
turn unit On at start up. Three other regulator terminals are available for optional use in vehicle systems. The P terminal is connected to the stator, and
may be connected to a tachometer or other device. The F terminal is connected internally to field positive, and may be used as a fault indicator. The S
terminal may be connected externally to a voltage, such as battery voltage, to sense voltage to be controlled.
The regulator voltage setting varies with temperature, and limits system voltage by controlling rotor field current. Unlike others regulators, this
regulator switches field current On and Off at a fixed frequency about 400 cycles per second. By varying On-Off time, correct average field current is
obtained to provide proper system voltage. At high speeds, the On time may be 10% and Off time 90%. At low speeds with high electrical loads,
On-Off time may be 90% and 10% respectively.
Alternator systems on some applications are controlled by a Body Control Module (BCM). If cause of a system malfunction cannot be determined
using the following test procedure, a problem in the electronic control system is indicated.
