Alternator & Regulator: Other Chevrolet RV Cutaway G30

CS SERIES

Regulator voltage varies to compensate for temperature. Voltage is regulated by controlling rotor field current. Regulator switches rotor field current "on" and "off" at a fixed frequency of approximately 400 cycles per second.

By controlling "on" and "off" time, correct system voltage can be obtained. During high speeds "on" time may be 10 percent and "off" time 90 percent. During low speeds with high electrical loads, "on" time may be 90 percent and "off" time 10 percent.

SI SERIES

A rectifier bridge, connected to stator windings, contains 6 diodes (3 positive and 3 negative) molded into an assembly. This rectifier bridge changes stator AC voltage into DC voltage, which appears at output terminal.

Alternator field current is supplied through a diode trio which is also connected to stator windings. A capacitor is mounted to end frame, protecting rectifier bridge and diodes from high voltage and suppressing radio interference noise.

Overcharged or Undercharged Battery

1. If an overcharging condition is suspected, run engine at a moderate speed. Connect a voltmeter across battery terminals. If voltmeter indicates more than 16 volts, replace alternator.
2. If an undercharging condition is suspected, disconnect 4-wire connector from alternator. Turn ignition on with engine off. Connect a voltmeter between terminal "L" in wiring harness and ground. Record reading.
3. If terminal "I" is used, connect voltmeter between terminal "I" and ground. Record reading. If voltmeter reads battery voltage, circuits are okay. If voltmeter reads zero, this indicates an open circuit between terminal checked and battery. Repair as necessary.

1. If an overcharging condition is suspected, attach a voltmeter across battery terminals. Run engine at a moderate speed with all accessories off. If voltmeter reads 15.5 volts or more, remove alternator for repair.
2. If an undercharging condition is suspected, turn ignition on. Connect a voltmeter from alternator "BAT" terminal to ground. Voltmeter should read 12 volts. Connect voltmeter between No. 1 terminal and ground. Voltmeter should read one volt or more.
3. Connect voltmeter between No. 2 terminal and ground. Voltmeter should read 12 volts. A zero reading on any connection indicates an open between connection and battery. Opens in the No. 2 lead may be between terminals at the crimp between harness wire and terminal, or in wire.

CS SERIES ALTERNATOR OUTPUT SPECIFICATIONS

SI SERIES ALTERNATOR OUTPUT SPECIFICATIONS